diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 47641271f2..8369138833 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -36,10 +36,7 @@ list(APPEND HHEADERS "${CMAKE_CURRENT_BINARY_DIR}/curl_config.h")
 
 # The rest of the build
 
-include_directories(
-  "${PROJECT_BINARY_DIR}/lib"  # for "curl_config.h"
-  "${PROJECT_SOURCE_DIR}/lib"  # for "curl_setup.h"
-)
+include_directories("${PROJECT_BINARY_DIR}/lib")  # for "curl_config.h"
 if(USE_ARES)
   include_directories(SYSTEM ${CARES_INCLUDE_DIRS})
 endif()
diff --git a/lib/Makefile.am b/lib/Makefile.am
index c810129ed7..9ce95eaee8 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -50,11 +50,9 @@ CFLAGS += @CURL_CFLAG_EXTRAS@
 #
 # $(top_srcdir)/include is for libcurl's external include files
 # $(top_builddir)/lib is for libcurl's generated lib/curl_config.h file
-# $(top_srcdir)/lib for libcurl's lib/curl_setup.h and other "private" files
 
 AM_CPPFLAGS = -I$(top_srcdir)/include        \
-              -I$(top_builddir)/lib          \
-              -I$(top_srcdir)/lib
+              -I$(top_builddir)/lib
 
 # Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
@@ -162,10 +160,8 @@ CS_1 =
 CS_ = $(CS_0)
 
 checksrc:
-	$(CHECKSRC)(@PERL@ $(top_srcdir)/scripts/checksrc.pl -D$(srcdir)         \
-	  -W$(srcdir)/libcurl_unity.c -W$(srcdir)/curl_config.h $(srcdir)/*.[ch] \
-	  $(srcdir)/vauth/*.[ch] $(srcdir)/vtls/*.[ch] $(srcdir)/vquic/*.[ch]    \
-	  $(srcdir)/vssh/*.[ch])
+	$(CHECKSRC)(@PERL@ $(top_srcdir)/scripts/checksrc.pl -D$(srcdir) \
+	$(CSOURCES) $(HHEADERS))
 
 if DEBUGBUILD
 # for debug builds, we scan the sources on all regular make invokes
diff --git a/lib/vauth/cleartext.c b/lib/vauth/cleartext.c
index 9dfefa3afc..4811394e19 100644
--- a/lib/vauth/cleartext.c
+++ b/lib/vauth/cleartext.c
@@ -25,23 +25,23 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if !defined(CURL_DISABLE_IMAP) || !defined(CURL_DISABLE_SMTP) ||       \
   !defined(CURL_DISABLE_POP3) || \
   (!defined(CURL_DISABLE_LDAP) && defined(USE_OPENLDAP))
 
 #include <curl/curl.h>
-#include "urldata.h"
+#include "../urldata.h"
 
-#include "vauth/vauth.h"
-#include "warnless.h"
-#include "sendf.h"
-#include "curl_printf.h"
+#include "vauth.h"
+#include "../warnless.h"
+#include "../sendf.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_create_plain_message()
diff --git a/lib/vauth/cram.c b/lib/vauth/cram.c
index c51c7285b4..d39b69a393 100644
--- a/lib/vauth/cram.c
+++ b/lib/vauth/cram.c
@@ -24,22 +24,22 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifndef CURL_DISABLE_DIGEST_AUTH
 
 #include <curl/curl.h>
-#include "urldata.h"
+#include "../urldata.h"
 
-#include "vauth/vauth.h"
-#include "curl_hmac.h"
-#include "curl_md5.h"
-#include "warnless.h"
-#include "curl_printf.h"
+#include "vauth.h"
+#include "../curl_hmac.h"
+#include "../curl_md5.h"
+#include "../warnless.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 /*
diff --git a/lib/vauth/digest.c b/lib/vauth/digest.c
index 024b7bb01a..d0b7687c04 100644
--- a/lib/vauth/digest.c
+++ b/lib/vauth/digest.c
@@ -25,30 +25,30 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifndef CURL_DISABLE_DIGEST_AUTH
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "vauth/digest.h"
-#include "urldata.h"
-#include "curl_base64.h"
-#include "curl_hmac.h"
-#include "curl_md5.h"
-#include "curl_sha256.h"
-#include "curl_sha512_256.h"
-#include "vtls/vtls.h"
-#include "warnless.h"
-#include "strparse.h"
-#include "strcase.h"
-#include "curl_printf.h"
-#include "rand.h"
+#include "vauth.h"
+#include "digest.h"
+#include "../urldata.h"
+#include "../curl_base64.h"
+#include "../curl_hmac.h"
+#include "../curl_md5.h"
+#include "../curl_sha256.h"
+#include "../curl_sha512_256.h"
+#include "../vtls/vtls.h"
+#include "../warnless.h"
+#include "../strparse.h"
+#include "../strcase.h"
+#include "../curl_printf.h"
+#include "../rand.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #ifndef USE_WINDOWS_SSPI
 #define SESSION_ALGO 1 /* for algos with this bit set */
diff --git a/lib/vauth/digest_sspi.c b/lib/vauth/digest_sspi.c
index ff8453541f..d3e9a23e62 100644
--- a/lib/vauth/digest_sspi.c
+++ b/lib/vauth/digest_sspi.c
@@ -25,25 +25,25 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_WINDOWS_SSPI) && !defined(CURL_DISABLE_DIGEST_AUTH)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "vauth/digest.h"
-#include "urldata.h"
-#include "warnless.h"
-#include "curl_multibyte.h"
-#include "sendf.h"
-#include "strdup.h"
-#include "strcase.h"
-#include "strerror.h"
+#include "vauth.h"
+#include "digest.h"
+#include "../urldata.h"
+#include "../warnless.h"
+#include "../curl_multibyte.h"
+#include "../sendf.h"
+#include "../strdup.h"
+#include "../strcase.h"
+#include "../strerror.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
 * Curl_auth_is_digest_supported()
diff --git a/lib/vauth/gsasl.c b/lib/vauth/gsasl.c
index ee11b6039d..3684c8f4b2 100644
--- a/lib/vauth/gsasl.c
+++ b/lib/vauth/gsasl.c
@@ -24,22 +24,22 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_GSASL
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "urldata.h"
-#include "sendf.h"
+#include "vauth.h"
+#include "../urldata.h"
+#include "../sendf.h"
 
 #include <gsasl.h>
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 bool Curl_auth_gsasl_is_supported(struct Curl_easy *data,
                                   const char *mech,
diff --git a/lib/vauth/krb5_gssapi.c b/lib/vauth/krb5_gssapi.c
index 3d06a472b2..b559040617 100644
--- a/lib/vauth/krb5_gssapi.c
+++ b/lib/vauth/krb5_gssapi.c
@@ -25,22 +25,22 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(HAVE_GSSAPI) && defined(USE_KERBEROS5)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "curl_sasl.h"
-#include "urldata.h"
-#include "curl_gssapi.h"
-#include "sendf.h"
-#include "curl_printf.h"
+#include "vauth.h"
+#include "../curl_sasl.h"
+#include "../urldata.h"
+#include "../curl_gssapi.h"
+#include "../sendf.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #if defined(__GNUC__) && defined(__APPLE__)
 #pragma GCC diagnostic push
diff --git a/lib/vauth/krb5_sspi.c b/lib/vauth/krb5_sspi.c
index 2b785538ba..f9abd952a5 100644
--- a/lib/vauth/krb5_sspi.c
+++ b/lib/vauth/krb5_sspi.c
@@ -24,21 +24,21 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_WINDOWS_SSPI) && defined(USE_KERBEROS5)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "urldata.h"
-#include "warnless.h"
-#include "curl_multibyte.h"
-#include "sendf.h"
+#include "vauth.h"
+#include "../urldata.h"
+#include "../warnless.h"
+#include "../curl_multibyte.h"
+#include "../sendf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_is_gssapi_supported()
diff --git a/lib/vauth/ntlm.c b/lib/vauth/ntlm.c
index 30298af1dd..46633ae1e6 100644
--- a/lib/vauth/ntlm.c
+++ b/lib/vauth/ntlm.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_NTLM) && !defined(USE_WINDOWS_SSPI)
 
@@ -35,24 +35,24 @@
 
 #define DEBUG_ME 0
 
-#include "urldata.h"
-#include "sendf.h"
-#include "curl_ntlm_core.h"
-#include "curl_gethostname.h"
-#include "curl_multibyte.h"
-#include "curl_md5.h"
-#include "warnless.h"
-#include "rand.h"
-#include "vtls/vtls.h"
-#include "strdup.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../curl_ntlm_core.h"
+#include "../curl_gethostname.h"
+#include "../curl_multibyte.h"
+#include "../curl_md5.h"
+#include "../warnless.h"
+#include "../rand.h"
+#include "../vtls/vtls.h"
+#include "../strdup.h"
 
-#include "vauth/vauth.h"
-#include "curl_endian.h"
-#include "curl_printf.h"
+#include "vauth.h"
+#include "../curl_endian.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 /* NTLM buffer fixed size, large enough for long user + host + domain */
diff --git a/lib/vauth/ntlm_sspi.c b/lib/vauth/ntlm_sspi.c
index 1bc4b2fd25..0e6651a3af 100644
--- a/lib/vauth/ntlm_sspi.c
+++ b/lib/vauth/ntlm_sspi.c
@@ -22,23 +22,23 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_WINDOWS_SSPI) && defined(USE_NTLM)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "urldata.h"
-#include "curl_ntlm_core.h"
-#include "warnless.h"
-#include "curl_multibyte.h"
-#include "sendf.h"
-#include "strdup.h"
+#include "vauth.h"
+#include "../urldata.h"
+#include "../curl_ntlm_core.h"
+#include "../warnless.h"
+#include "../curl_multibyte.h"
+#include "../sendf.h"
+#include "../strdup.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_is_ntlm_supported()
diff --git a/lib/vauth/oauth2.c b/lib/vauth/oauth2.c
index dc94afa365..dec2d0b2aa 100644
--- a/lib/vauth/oauth2.c
+++ b/lib/vauth/oauth2.c
@@ -24,22 +24,22 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if !defined(CURL_DISABLE_IMAP) || !defined(CURL_DISABLE_SMTP) || \
   !defined(CURL_DISABLE_POP3) || \
   (!defined(CURL_DISABLE_LDAP) && defined(USE_OPENLDAP))
 
 #include <curl/curl.h>
-#include "urldata.h"
+#include "../urldata.h"
 
-#include "vauth/vauth.h"
-#include "warnless.h"
-#include "curl_printf.h"
+#include "vauth.h"
+#include "../warnless.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_create_oauth_bearer_message()
diff --git a/lib/vauth/spnego_gssapi.c b/lib/vauth/spnego_gssapi.c
index eb415183e8..0b4a7b6d2e 100644
--- a/lib/vauth/spnego_gssapi.c
+++ b/lib/vauth/spnego_gssapi.c
@@ -24,23 +24,23 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(HAVE_GSSAPI) && defined(USE_SPNEGO)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "urldata.h"
-#include "curl_base64.h"
-#include "curl_gssapi.h"
-#include "warnless.h"
-#include "curl_multibyte.h"
-#include "sendf.h"
+#include "vauth.h"
+#include "../urldata.h"
+#include "../curl_base64.h"
+#include "../curl_gssapi.h"
+#include "../warnless.h"
+#include "../curl_multibyte.h"
+#include "../sendf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #if defined(__GNUC__) && defined(__APPLE__)
 #pragma GCC diagnostic push
diff --git a/lib/vauth/spnego_sspi.c b/lib/vauth/spnego_sspi.c
index 9d7333c5b1..8603098fc1 100644
--- a/lib/vauth/spnego_sspi.c
+++ b/lib/vauth/spnego_sspi.c
@@ -24,23 +24,23 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_WINDOWS_SSPI) && defined(USE_SPNEGO)
 
 #include <curl/curl.h>
 
-#include "vauth/vauth.h"
-#include "urldata.h"
-#include "curl_base64.h"
-#include "warnless.h"
-#include "curl_multibyte.h"
-#include "sendf.h"
-#include "strerror.h"
+#include "vauth.h"
+#include "../urldata.h"
+#include "../curl_base64.h"
+#include "../warnless.h"
+#include "../curl_multibyte.h"
+#include "../sendf.h"
+#include "../strerror.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_is_spnego_supported()
diff --git a/lib/vauth/vauth.c b/lib/vauth/vauth.c
index 171e53fb13..56854863ec 100644
--- a/lib/vauth/vauth.c
+++ b/lib/vauth/vauth.c
@@ -22,19 +22,19 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #include <curl/curl.h>
 
 #include "vauth.h"
-#include "urldata.h"
-#include "strcase.h"
-#include "curl_multibyte.h"
-#include "curl_printf.h"
+#include "../urldata.h"
+#include "../strcase.h"
+#include "../curl_multibyte.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Curl_auth_build_spn()
diff --git a/lib/vauth/vauth.h b/lib/vauth/vauth.h
index 7e823484f6..7ff0b05595 100644
--- a/lib/vauth/vauth.h
+++ b/lib/vauth/vauth.h
@@ -26,7 +26,7 @@
 
 #include <curl/curl.h>
 
-#include "bufref.h"
+#include "../bufref.h"
 
 struct Curl_easy;
 
diff --git a/lib/vquic/curl_msh3.c b/lib/vquic/curl_msh3.c
index a5f2785b96..d473b3a19f 100644
--- a/lib/vquic/curl_msh3.c
+++ b/lib/vquic/curl_msh3.c
@@ -22,31 +22,31 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_MSH3
 
-#include "urldata.h"
-#include "hash.h"
-#include "hash_offt.h"
-#include "timeval.h"
-#include "multiif.h"
-#include "sendf.h"
-#include "curl_trc.h"
-#include "cfilters.h"
-#include "cf-socket.h"
-#include "connect.h"
-#include "progress.h"
-#include "http1.h"
+#include "../urldata.h"
+#include "../hash.h"
+#include "../hash_offt.h"
+#include "../timeval.h"
+#include "../multiif.h"
+#include "../sendf.h"
+#include "../curl_trc.h"
+#include "../cfilters.h"
+#include "../cf-socket.h"
+#include "../connect.h"
+#include "../progress.h"
+#include "../http1.h"
 #include "curl_msh3.h"
-#include "socketpair.h"
-#include "vtls/vtls.h"
-#include "vquic/vquic.h"
+#include "../socketpair.h"
+#include "../vtls/vtls.h"
+#include "vquic.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #ifdef CURL_DISABLE_SOCKETPAIR
 #error "MSH3 cannot be build with CURL_DISABLE_SOCKETPAIR set"
diff --git a/lib/vquic/curl_msh3.h b/lib/vquic/curl_msh3.h
index 33931f59bb..d2862c2d89 100644
--- a/lib/vquic/curl_msh3.h
+++ b/lib/vquic/curl_msh3.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_MSH3
 
diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index f96cc80420..0d30cde4aa 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_NGTCP2) && defined(USE_NGHTTP3)
 #include <ngtcp2/ngtcp2.h>
@@ -35,46 +35,46 @@
 #else
 #include <ngtcp2/ngtcp2_crypto_quictls.h>
 #endif
-#include "vtls/openssl.h"
+#include "../vtls/openssl.h"
 #elif defined(USE_GNUTLS)
 #include <ngtcp2/ngtcp2_crypto_gnutls.h>
-#include "vtls/gtls.h"
+#include "../vtls/gtls.h"
 #elif defined(USE_WOLFSSL)
 #include <ngtcp2/ngtcp2_crypto_wolfssl.h>
-#include "vtls/wolfssl.h"
+#include "../vtls/wolfssl.h"
 #endif
 
-#include "urldata.h"
-#include "hash_offt.h"
-#include "sendf.h"
-#include "strdup.h"
-#include "rand.h"
-#include "multiif.h"
-#include "strcase.h"
-#include "cfilters.h"
-#include "cf-socket.h"
-#include "connect.h"
-#include "progress.h"
-#include "strerror.h"
-#include "dynbuf.h"
-#include "http1.h"
-#include "select.h"
-#include "inet_pton.h"
-#include "transfer.h"
+#include "../urldata.h"
+#include "../hash_offt.h"
+#include "../sendf.h"
+#include "../strdup.h"
+#include "../rand.h"
+#include "../multiif.h"
+#include "../strcase.h"
+#include "../cfilters.h"
+#include "../cf-socket.h"
+#include "../connect.h"
+#include "../progress.h"
+#include "../strerror.h"
+#include "../dynbuf.h"
+#include "../http1.h"
+#include "../select.h"
+#include "../inet_pton.h"
+#include "../transfer.h"
 #include "vquic.h"
 #include "vquic_int.h"
 #include "vquic-tls.h"
-#include "vtls/keylog.h"
-#include "vtls/vtls.h"
-#include "vtls/vtls_scache.h"
+#include "../vtls/keylog.h"
+#include "../vtls/vtls.h"
+#include "../vtls/vtls_scache.h"
 #include "curl_ngtcp2.h"
 
-#include "warnless.h"
+#include "../warnless.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 #define QUIC_MAX_STREAMS (256*1024)
diff --git a/lib/vquic/curl_ngtcp2.h b/lib/vquic/curl_ngtcp2.h
index db3e611bd0..f653b8033e 100644
--- a/lib/vquic/curl_ngtcp2.h
+++ b/lib/vquic/curl_ngtcp2.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_NGTCP2) && defined(USE_NGHTTP3)
 
@@ -44,7 +44,7 @@
 
 struct Curl_cfilter;
 
-#include "urldata.h"
+#include "../urldata.h"
 
 void Curl_ngtcp2_ver(char *p, size_t len);
 
diff --git a/lib/vquic/curl_osslq.c b/lib/vquic/curl_osslq.c
index cca0ed7d0b..c2d069894d 100644
--- a/lib/vquic/curl_osslq.c
+++ b/lib/vquic/curl_osslq.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_OPENSSL_QUIC) && defined(USE_NGHTTP3)
 
@@ -31,36 +31,36 @@
 #include <openssl/err.h>
 #include <nghttp3/nghttp3.h>
 
-#include "urldata.h"
-#include "hash.h"
-#include "sendf.h"
-#include "strdup.h"
-#include "rand.h"
-#include "multiif.h"
-#include "strcase.h"
-#include "cfilters.h"
-#include "cf-socket.h"
-#include "connect.h"
-#include "progress.h"
-#include "strerror.h"
-#include "dynbuf.h"
-#include "http1.h"
-#include "select.h"
-#include "inet_pton.h"
+#include "../urldata.h"
+#include "../hash.h"
+#include "../sendf.h"
+#include "../strdup.h"
+#include "../rand.h"
+#include "../multiif.h"
+#include "../strcase.h"
+#include "../cfilters.h"
+#include "../cf-socket.h"
+#include "../connect.h"
+#include "../progress.h"
+#include "../strerror.h"
+#include "../dynbuf.h"
+#include "../http1.h"
+#include "../select.h"
+#include "../inet_pton.h"
 #include "vquic.h"
 #include "vquic_int.h"
 #include "vquic-tls.h"
-#include "vtls/keylog.h"
-#include "vtls/vtls.h"
-#include "vtls/openssl.h"
+#include "../vtls/keylog.h"
+#include "../vtls/vtls.h"
+#include "../vtls/openssl.h"
 #include "curl_osslq.h"
 
-#include "warnless.h"
+#include "../warnless.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* A stream window is the maximum amount we need to buffer for
  * each active transfer. We use HTTP/3 flow control and only ACK
diff --git a/lib/vquic/curl_osslq.h b/lib/vquic/curl_osslq.h
index 0e12d7023e..a2809c92bc 100644
--- a/lib/vquic/curl_osslq.h
+++ b/lib/vquic/curl_osslq.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_OPENSSL_QUIC) && defined(USE_NGHTTP3)
 
@@ -34,7 +34,7 @@
 
 struct Curl_cfilter;
 
-#include "urldata.h"
+#include "../urldata.h"
 
 void Curl_osslq_ver(char *p, size_t len);
 
diff --git a/lib/vquic/curl_quiche.c b/lib/vquic/curl_quiche.c
index 4e4c07a965..d48f783026 100644
--- a/lib/vquic/curl_quiche.c
+++ b/lib/vquic/curl_quiche.c
@@ -22,40 +22,40 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_QUICHE
 #include <quiche.h>
 #include <openssl/err.h>
 #include <openssl/ssl.h>
-#include "bufq.h"
-#include "hash_offt.h"
-#include "urldata.h"
-#include "cfilters.h"
-#include "cf-socket.h"
-#include "sendf.h"
-#include "strdup.h"
-#include "rand.h"
-#include "strcase.h"
-#include "multiif.h"
-#include "connect.h"
-#include "progress.h"
-#include "strerror.h"
-#include "http1.h"
+#include "../bufq.h"
+#include "../hash_offt.h"
+#include "../urldata.h"
+#include "../cfilters.h"
+#include "../cf-socket.h"
+#include "../sendf.h"
+#include "../strdup.h"
+#include "../rand.h"
+#include "../strcase.h"
+#include "../multiif.h"
+#include "../connect.h"
+#include "../progress.h"
+#include "../strerror.h"
+#include "../http1.h"
 #include "vquic.h"
 #include "vquic_int.h"
 #include "vquic-tls.h"
 #include "curl_quiche.h"
-#include "transfer.h"
-#include "inet_pton.h"
-#include "vtls/openssl.h"
-#include "vtls/keylog.h"
-#include "vtls/vtls.h"
+#include "../transfer.h"
+#include "../inet_pton.h"
+#include "../vtls/openssl.h"
+#include "../vtls/keylog.h"
+#include "../vtls/vtls.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* HTTP/3 error values defined in RFC 9114, ch. 8.1 */
 #define CURL_H3_NO_ERROR  (0x0100)
diff --git a/lib/vquic/curl_quiche.h b/lib/vquic/curl_quiche.h
index bce781c1bc..9832687bdc 100644
--- a/lib/vquic/curl_quiche.h
+++ b/lib/vquic/curl_quiche.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_QUICHE
 
diff --git a/lib/vquic/vquic-tls.c b/lib/vquic/vquic-tls.c
index ec792a65a2..fa29d2e3dc 100644
--- a/lib/vquic/vquic-tls.c
+++ b/lib/vquic/vquic-tls.c
@@ -22,41 +22,41 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_HTTP3) && \
   (defined(USE_OPENSSL) || defined(USE_GNUTLS) || defined(USE_WOLFSSL))
 
 #ifdef USE_OPENSSL
 #include <openssl/err.h>
-#include "vtls/openssl.h"
+#include "../vtls/openssl.h"
 #elif defined(USE_GNUTLS)
 #include <gnutls/abstract.h>
 #include <gnutls/gnutls.h>
 #include <gnutls/x509.h>
 #include <gnutls/crypto.h>
 #include <nettle/sha2.h>
-#include "vtls/gtls.h"
+#include "../vtls/gtls.h"
 #elif defined(USE_WOLFSSL)
 #include <wolfssl/options.h>
 #include <wolfssl/ssl.h>
 #include <wolfssl/quic.h>
-#include "vtls/wolfssl.h"
+#include "../vtls/wolfssl.h"
 #endif
 
-#include "urldata.h"
-#include "curl_trc.h"
-#include "cfilters.h"
-#include "multiif.h"
-#include "vtls/keylog.h"
-#include "vtls/vtls.h"
-#include "vtls/vtls_scache.h"
+#include "../urldata.h"
+#include "../curl_trc.h"
+#include "../cfilters.h"
+#include "../multiif.h"
+#include "../vtls/keylog.h"
+#include "../vtls/vtls.h"
+#include "../vtls/vtls_scache.h"
 #include "vquic-tls.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 CURLcode Curl_vquic_tls_init(struct curl_tls_ctx *ctx,
                              struct Curl_cfilter *cf,
diff --git a/lib/vquic/vquic-tls.h b/lib/vquic/vquic-tls.h
index 453f876929..bf29eecc91 100644
--- a/lib/vquic/vquic-tls.h
+++ b/lib/vquic/vquic-tls.h
@@ -24,16 +24,16 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
-#include "bufq.h"
-#include "vtls/vtls.h"
-#include "vtls/vtls_int.h"
-#include "vtls/openssl.h"
+#include "../curl_setup.h"
+#include "../bufq.h"
+#include "../vtls/vtls.h"
+#include "../vtls/vtls_int.h"
+#include "../vtls/openssl.h"
 
 #if defined(USE_HTTP3) && \
   (defined(USE_OPENSSL) || defined(USE_GNUTLS) || defined(USE_WOLFSSL))
 
-#include "vtls/wolfssl.h"
+#include "../vtls/wolfssl.h"
 
 struct ssl_peer;
 struct Curl_ssl_session;
diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index eb08ce7a22..9f2361f885 100644
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef HAVE_NETINET_UDP_H
 #include <netinet/udp.h>
@@ -30,26 +30,26 @@
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
-#include "urldata.h"
-#include "bufq.h"
-#include "dynbuf.h"
-#include "cfilters.h"
-#include "curl_trc.h"
+#include "../urldata.h"
+#include "../bufq.h"
+#include "../dynbuf.h"
+#include "../cfilters.h"
+#include "../curl_trc.h"
 #include "curl_msh3.h"
 #include "curl_ngtcp2.h"
 #include "curl_osslq.h"
 #include "curl_quiche.h"
-#include "multiif.h"
-#include "rand.h"
+#include "../multiif.h"
+#include "../rand.h"
 #include "vquic.h"
 #include "vquic_int.h"
-#include "strerror.h"
-#include "strparse.h"
+#include "../strerror.h"
+#include "../strparse.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 #ifdef USE_HTTP3
diff --git a/lib/vquic/vquic.h b/lib/vquic/vquic.h
index 1cd3e258f4..2c8f89114e 100644
--- a/lib/vquic/vquic.h
+++ b/lib/vquic/vquic.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_HTTP3
 struct Curl_cfilter;
diff --git a/lib/vquic/vquic_int.h b/lib/vquic/vquic_int.h
index 754e1f5910..894b7695c8 100644
--- a/lib/vquic/vquic_int.h
+++ b/lib/vquic/vquic_int.h
@@ -24,8 +24,8 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
-#include "bufq.h"
+#include "../curl_setup.h"
+#include "../bufq.h"
 
 #ifdef USE_HTTP3
 
diff --git a/lib/vssh/curl_path.c b/lib/vssh/curl_path.c
index 61452a4252..caff85b646 100644
--- a/lib/vssh/curl_path.c
+++ b/lib/vssh/curl_path.c
@@ -22,15 +22,15 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_SSH)
 
 #include "curl_path.h"
 #include <curl/curl.h>
-#include "curl_memory.h"
-#include "escape.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../escape.h"
+#include "../memdebug.h"
 
 #define MAX_SSHPATH_LEN 100000 /* arbitrary */
 
diff --git a/lib/vssh/curl_path.h b/lib/vssh/curl_path.h
index 8e984174d7..1c167f9660 100644
--- a/lib/vssh/curl_path.h
+++ b/lib/vssh/curl_path.h
@@ -24,9 +24,9 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 #include <curl/curl.h>
-#include "urldata.h"
+#include "../urldata.h"
 
 CURLcode Curl_getworkingpath(struct Curl_easy *data,
                              char *homedir,
diff --git a/lib/vssh/libssh.c b/lib/vssh/libssh.c
index b20f82adbb..7ed4fbe3ea 100644
--- a/lib/vssh/libssh.c
+++ b/lib/vssh/libssh.c
@@ -25,7 +25,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_LIBSSH
 
@@ -46,29 +46,29 @@
 #endif
 
 #include <curl/curl.h>
-#include "urldata.h"
-#include "sendf.h"
-#include "hostip.h"
-#include "progress.h"
-#include "transfer.h"
-#include "escape.h"
-#include "http.h"               /* for HTTP proxy tunnel stuff */
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../hostip.h"
+#include "../progress.h"
+#include "../transfer.h"
+#include "../escape.h"
+#include "../http.h"               /* for HTTP proxy tunnel stuff */
 #include "ssh.h"
-#include "url.h"
-#include "speedcheck.h"
-#include "getinfo.h"
-#include "strdup.h"
-#include "strcase.h"
-#include "vtls/vtls.h"
-#include "cfilters.h"
-#include "connect.h"
-#include "inet_ntop.h"
-#include "parsedate.h"          /* for the week day and month names */
-#include "sockaddr.h"           /* required for Curl_sockaddr_storage */
-#include "strparse.h"
-#include "multiif.h"
-#include "select.h"
-#include "warnless.h"
+#include "../url.h"
+#include "../speedcheck.h"
+#include "../getinfo.h"
+#include "../strdup.h"
+#include "../strcase.h"
+#include "../vtls/vtls.h"
+#include "../cfilters.h"
+#include "../connect.h"
+#include "../inet_ntop.h"
+#include "../parsedate.h"          /* for the week day and month names */
+#include "../sockaddr.h"           /* required for Curl_sockaddr_storage */
+#include "../strparse.h"
+#include "../multiif.h"
+#include "../select.h"
+#include "../warnless.h"
 #include "curl_path.h"
 
 #ifdef HAVE_SYS_STAT_H
@@ -82,9 +82,9 @@
 #endif
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* A recent macro provided by libssh. Or make our own. */
 #ifndef SSH_STRING_FREE_CHAR
diff --git a/lib/vssh/libssh2.c b/lib/vssh/libssh2.c
index 58372478f1..ce95e8ddf9 100644
--- a/lib/vssh/libssh2.c
+++ b/lib/vssh/libssh2.c
@@ -24,7 +24,7 @@
 
 /* #define CURL_LIBSSH2_DEBUG */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_LIBSSH2
 
@@ -49,38 +49,37 @@
 #endif
 
 #include <curl/curl.h>
-#include "urldata.h"
-#include "sendf.h"
-#include "hostip.h"
-#include "progress.h"
-#include "transfer.h"
-#include "escape.h"
-#include "http.h" /* for HTTP proxy tunnel stuff */
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../hostip.h"
+#include "../progress.h"
+#include "../transfer.h"
+#include "../escape.h"
+#include "../http.h" /* for HTTP proxy tunnel stuff */
 #include "ssh.h"
-#include "url.h"
-#include "speedcheck.h"
-#include "getinfo.h"
-#include "strdup.h"
-#include "strcase.h"
-#include "vtls/vtls.h"
-#include "cfilters.h"
-#include "connect.h"
-#include "inet_ntop.h"
-#include "parsedate.h" /* for the week day and month names */
-#include "sockaddr.h" /* required for Curl_sockaddr_storage */
-#include "multiif.h"
-#include "select.h"
-#include "warnless.h"
+#include "../url.h"
+#include "../speedcheck.h"
+#include "../getinfo.h"
+#include "../strdup.h"
+#include "../strcase.h"
+#include "../vtls/vtls.h"
+#include "../cfilters.h"
+#include "../connect.h"
+#include "../inet_ntop.h"
+#include "../parsedate.h" /* for the week day and month names */
+#include "../sockaddr.h" /* required for Curl_sockaddr_storage */
+#include "../multiif.h"
+#include "../select.h"
+#include "../warnless.h"
 #include "curl_path.h"
-#include "strparse.h"
-#include <curl_base64.h> /* for base64 encoding/decoding */
-#include <curl_sha256.h>
-
+#include "../strparse.h"
+#include "../curl_base64.h" /* for base64 encoding/decoding */
+#include "../curl_sha256.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* Local functions: */
 static const char *sftp_libssh2_strerror(unsigned long err);
diff --git a/lib/vssh/ssh.h b/lib/vssh/ssh.h
index e882ff3d33..3c88c4e0b0 100644
--- a/lib/vssh/ssh.h
+++ b/lib/vssh/ssh.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_LIBSSH2)
 #include <libssh2.h>
diff --git a/lib/vssh/wolfssh.c b/lib/vssh/wolfssh.c
index 031b55da91..2b81e56969 100644
--- a/lib/vssh/wolfssh.c
+++ b/lib/vssh/wolfssh.c
@@ -22,29 +22,29 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_WOLFSSH
 
 #include <limits.h>
 
-#include "urldata.h"
-#include "cfilters.h"
-#include "connect.h"
-#include "sendf.h"
-#include "progress.h"
+#include "../urldata.h"
+#include "../cfilters.h"
+#include "../connect.h"
+#include "../sendf.h"
+#include "../progress.h"
 #include "curl_path.h"
-#include "transfer.h"
-#include "speedcheck.h"
-#include "select.h"
-#include "multiif.h"
-#include "warnless.h"
-#include "strdup.h"
+#include "../transfer.h"
+#include "../speedcheck.h"
+#include "../select.h"
+#include "../multiif.h"
+#include "../warnless.h"
+#include "../strdup.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 static CURLcode wssh_connect(struct Curl_easy *data, bool *done);
 static CURLcode wssh_multi_statemach(struct Curl_easy *data, bool *done);
diff --git a/lib/vtls/bearssl.c b/lib/vtls/bearssl.c
index 995f97d3f9..39abf0f0c1 100644
--- a/lib/vtls/bearssl.c
+++ b/lib/vtls/bearssl.c
@@ -21,7 +21,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_BEARSSL
 
@@ -29,20 +29,20 @@
 
 #include "bearssl.h"
 #include "cipher_suite.h"
-#include "urldata.h"
-#include "sendf.h"
-#include "inet_pton.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
-#include "connect.h"
-#include "select.h"
-#include "multiif.h"
-#include "curl_printf.h"
+#include "../connect.h"
+#include "../select.h"
+#include "../multiif.h"
+#include "../curl_printf.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 struct x509_context {
   const br_x509_class *vtable;
diff --git a/lib/vtls/bearssl.h b/lib/vtls/bearssl.h
index b3651b092c..8bb254f7da 100644
--- a/lib/vtls/bearssl.h
+++ b/lib/vtls/bearssl.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_BEARSSL
 
diff --git a/lib/vtls/cipher_suite.c b/lib/vtls/cipher_suite.c
index e9797d43d0..d058bd3f0e 100644
--- a/lib/vtls/cipher_suite.c
+++ b/lib/vtls/cipher_suite.c
@@ -21,13 +21,13 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_SECTRANSP) || defined(USE_MBEDTLS) || \
     defined(USE_BEARSSL) || defined(USE_RUSTLS)
 #include "cipher_suite.h"
-#include "curl_printf.h"
-#include "strcase.h"
+#include "../curl_printf.h"
+#include "../strcase.h"
 #include <string.h>
 
 /*
diff --git a/lib/vtls/cipher_suite.h b/lib/vtls/cipher_suite.h
index 6d980103a5..cd556db10f 100644
--- a/lib/vtls/cipher_suite.h
+++ b/lib/vtls/cipher_suite.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_SECTRANSP) || defined(USE_MBEDTLS) || \
     defined(USE_BEARSSL) || defined(USE_RUSTLS)
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index 7db06e759a..8d13312648 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -30,7 +30,7 @@
  * since they were not present in 1.0.X.
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_GNUTLS
 
@@ -40,28 +40,28 @@
 #include <gnutls/crypto.h>
 #include <nettle/sha2.h>
 
-#include "urldata.h"
-#include "sendf.h"
-#include "inet_pton.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
 #include "keylog.h"
 #include "gtls.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
-#include "vauth/vauth.h"
-#include "parsedate.h"
-#include "connect.h" /* for the connect timeout */
-#include "progress.h"
-#include "select.h"
-#include "strcase.h"
-#include "strdup.h"
-#include "warnless.h"
+#include "../vauth/vauth.h"
+#include "../parsedate.h"
+#include "../connect.h" /* for the connect timeout */
+#include "../progress.h"
+#include "../select.h"
+#include "../strcase.h"
+#include "../strdup.h"
+#include "../warnless.h"
 #include "x509asn1.h"
-#include "multiif.h"
-#include "curl_printf.h"
-#include "curl_memory.h"
+#include "../multiif.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
 /* The last #include file should be: */
-#include "memdebug.h"
+#include "../memdebug.h"
 
 /* Enable GnuTLS debugging by defining GTLSDEBUG */
 /*#define GTLSDEBUG */
diff --git a/lib/vtls/gtls.h b/lib/vtls/gtls.h
index d5e5c40c72..7366813437 100644
--- a/lib/vtls/gtls.h
+++ b/lib/vtls/gtls.h
@@ -24,13 +24,13 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 #include <curl/curl.h>
 
 #ifdef USE_GNUTLS
 
 #include <gnutls/gnutls.h>
-#include "timeval.h"
+#include "../timeval.h"
 
 #ifdef HAVE_GNUTLS_SRP
 /* the function exists */
diff --git a/lib/vtls/hostcheck.c b/lib/vtls/hostcheck.c
index e46439a5ec..8ca69941e8 100644
--- a/lib/vtls/hostcheck.c
+++ b/lib/vtls/hostcheck.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_OPENSSL)                        \
   || defined(USE_SCHANNEL)
@@ -34,15 +34,14 @@
 #ifdef HAVE_NETINET_IN6_H
 #include <netinet/in6.h>
 #endif
-#include "curl_memrchr.h"
-
+#include "../curl_memrchr.h"
 #include "hostcheck.h"
-#include "strcase.h"
-#include "hostip.h"
+#include "../strcase.h"
+#include "../hostip.h"
 
-#include "curl_memory.h"
+#include "../curl_memory.h"
 /* The last #include file should be: */
-#include "memdebug.h"
+#include "../memdebug.h"
 
 /* check the two input strings with given length, but do not
    assume they end in nul-bytes */
diff --git a/lib/vtls/keylog.c b/lib/vtls/keylog.c
index e4a8040e5a..8f4880cf8e 100644
--- a/lib/vtls/keylog.c
+++ b/lib/vtls/keylog.c
@@ -21,7 +21,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_OPENSSL) || \
   defined(USE_GNUTLS) || \
@@ -32,11 +32,11 @@
 
 #include "keylog.h"
 #include <curl/curl.h>
-#include "escape.h"
+#include "../escape.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* The fp for the open SSLKEYLOGFILE, or NULL if not open */
 static FILE *keylog_file_fp;
diff --git a/lib/vtls/keylog.h b/lib/vtls/keylog.h
index c87e549279..a00a225616 100644
--- a/lib/vtls/keylog.h
+++ b/lib/vtls/keylog.h
@@ -23,7 +23,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #define KEYLOG_LABEL_MAXLEN (sizeof("CLIENT_HANDSHAKE_TRAFFIC_SECRET") - 1)
 
diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index f50bed81ed..c13be87aea 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -29,7 +29,7 @@
  *
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_MBEDTLS
 
@@ -57,26 +57,26 @@
 #endif /* MBEDTLS_VERSION_MAJOR >= 2 */
 
 #include "cipher_suite.h"
-#include "strcase.h"
-#include "urldata.h"
-#include "sendf.h"
-#include "inet_pton.h"
+#include "../strcase.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
 #include "mbedtls.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
 #include "x509asn1.h"
-#include "parsedate.h"
-#include "connect.h" /* for the connect timeout */
-#include "select.h"
-#include "multiif.h"
+#include "../parsedate.h"
+#include "../connect.h" /* for the connect timeout */
+#include "../select.h"
+#include "../multiif.h"
 #include "mbedtls_threadlock.h"
-#include "strdup.h"
+#include "../strdup.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* ALPN for http2 */
 #if defined(USE_HTTP2) && defined(MBEDTLS_SSL_ALPN)
diff --git a/lib/vtls/mbedtls.h b/lib/vtls/mbedtls.h
index d8a0a06eb6..3876fe36fc 100644
--- a/lib/vtls/mbedtls.h
+++ b/lib/vtls/mbedtls.h
@@ -24,7 +24,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_MBEDTLS
 
diff --git a/lib/vtls/mbedtls_threadlock.c b/lib/vtls/mbedtls_threadlock.c
index b96a904fcb..682c221852 100644
--- a/lib/vtls/mbedtls_threadlock.c
+++ b/lib/vtls/mbedtls_threadlock.c
@@ -22,7 +22,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_MBEDTLS) &&                                     \
   ((defined(USE_THREADS_POSIX) && defined(HAVE_PTHREAD_H)) ||   \
@@ -36,10 +36,10 @@
 #endif
 
 #include "mbedtls_threadlock.h"
-#include "curl_printf.h"
-#include "curl_memory.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
 /* The last #include file should be: */
-#include "memdebug.h"
+#include "../memdebug.h"
 
 /* number of thread locks */
 #define NUMT                    2
diff --git a/lib/vtls/mbedtls_threadlock.h b/lib/vtls/mbedtls_threadlock.h
index 484626852f..9402af6e41 100644
--- a/lib/vtls/mbedtls_threadlock.h
+++ b/lib/vtls/mbedtls_threadlock.h
@@ -24,7 +24,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_MBEDTLS
 
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 4d5e1be29e..4c068adc6b 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -27,7 +27,7 @@
  * but vtls.c should ever call or use these functions.
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_QUICHE) || defined(USE_OPENSSL)
 
@@ -45,26 +45,26 @@
 #undef OCSP_RESPONSE
 #endif
 
-#include "urldata.h"
-#include "sendf.h"
-#include "formdata.h" /* for the boundary function */
-#include "url.h" /* for the ssl config check function */
-#include "inet_pton.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../formdata.h" /* for the boundary function */
+#include "../url.h" /* for the ssl config check function */
+#include "../inet_pton.h"
 #include "openssl.h"
-#include "connect.h"
-#include "slist.h"
-#include "select.h"
+#include "../connect.h"
+#include "../slist.h"
+#include "../select.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
-#include "vauth/vauth.h"
+#include "../vauth/vauth.h"
 #include "keylog.h"
-#include "strcase.h"
+#include "../strcase.h"
 #include "hostcheck.h"
-#include "multiif.h"
-#include "strdup.h"
-#include "strerror.h"
-#include "curl_printf.h"
+#include "../multiif.h"
+#include "../strdup.h"
+#include "../strerror.h"
+#include "../curl_printf.h"
 
 #include <openssl/ssl.h>
 #include <openssl/rand.h>
@@ -119,11 +119,11 @@
 #define OPENSSL_HAS_PROVIDERS
 #endif
 
-#include "warnless.h"
+#include "../warnless.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* Uncomment the ALLOW_RENEG line to a real #define if you want to allow TLS
    renegotiations when built with BoringSSL. Renegotiating is non-compliant
diff --git a/lib/vtls/openssl.h b/lib/vtls/openssl.h
index bc27c2291b..8d063e25ac 100644
--- a/lib/vtls/openssl.h
+++ b/lib/vtls/openssl.h
@@ -24,7 +24,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_OPENSSL
 /*
@@ -35,7 +35,7 @@
 #include <openssl/ossl_typ.h>
 #include <openssl/ssl.h>
 
-#include "urldata.h"
+#include "../urldata.h"
 
 /*
  * Whether SSL_CTX_set_keylog_callback is available.
diff --git a/lib/vtls/rustls.c b/lib/vtls/rustls.c
index 0087d5cbf7..695988ea0f 100644
--- a/lib/vtls/rustls.c
+++ b/lib/vtls/rustls.c
@@ -24,22 +24,22 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_RUSTLS
 
-#include "curl_printf.h"
+#include "../curl_printf.h"
 
 #include <rustls.h>
 
-#include "inet_pton.h"
-#include "urldata.h"
-#include "sendf.h"
+#include "../inet_pton.h"
+#include "../urldata.h"
+#include "../sendf.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "rustls.h"
 #include "keylog.h"
-#include "strerror.h"
+#include "../strerror.h"
 #include "cipher_suite.h"
 #include "x509asn1.h"
 
diff --git a/lib/vtls/rustls.h b/lib/vtls/rustls.h
index bfbe23de3e..74d39d4d11 100644
--- a/lib/vtls/rustls.h
+++ b/lib/vtls/rustls.h
@@ -25,7 +25,7 @@
 #ifndef HEADER_CURL_RUSTLS_H
 #define HEADER_CURL_RUSTLS_H
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_RUSTLS
 
diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index 6c63df2cd9..f5589a3096 100644
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -29,7 +29,7 @@
  * but vtls.c should ever call or use these functions.
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SCHANNEL
 
@@ -42,25 +42,25 @@
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
-#include "strcase.h"
-#include "sendf.h"
-#include "connect.h" /* for the connect timeout */
-#include "strerror.h"
-#include "select.h" /* for the socket readiness */
-#include "inet_pton.h" /* for IP addr SNI check */
-#include "curl_multibyte.h"
-#include "warnless.h"
+#include "../strcase.h"
+#include "../sendf.h"
+#include "../connect.h" /* for the connect timeout */
+#include "../strerror.h"
+#include "../select.h" /* for the socket readiness */
+#include "../inet_pton.h" /* for IP addr SNI check */
+#include "../curl_multibyte.h"
+#include "../warnless.h"
 #include "x509asn1.h"
-#include "curl_printf.h"
-#include "multiif.h"
-#include "system_win32.h"
-#include "version_win32.h"
-#include "rand.h"
-#include "strparse.h"
+#include "../curl_printf.h"
+#include "../multiif.h"
+#include "../system_win32.h"
+#include "../version_win32.h"
+#include "../rand.h"
+#include "../strparse.h"
 
 /* The last #include file should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /* Some verbose debug messages are wrapped by SCH_DEV() instead of DEBUGF()
  * and only shown if CURL_SCHANNEL_DEV_DEBUG was defined at build time. These
diff --git a/lib/vtls/schannel.h b/lib/vtls/schannel.h
index 69f1baddb8..c3512dd132 100644
--- a/lib/vtls/schannel.h
+++ b/lib/vtls/schannel.h
@@ -24,7 +24,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SCHANNEL
 
@@ -50,10 +50,10 @@
 
 #include <schnlsp.h>
 #include <schannel.h>
-#include "curl_sspi.h"
+#include "../curl_sspi.h"
 
-#include "cfilters.h"
-#include "urldata.h"
+#include "../cfilters.h"
+#include "../urldata.h"
 
 /* <wincrypt.h> has been included via the above <schnlsp.h>.
  * Or in case of ldap.c, it was included via <winldap.h>.
diff --git a/lib/vtls/schannel_int.h b/lib/vtls/schannel_int.h
index 81476bc6d8..f9513b31f9 100644
--- a/lib/vtls/schannel_int.h
+++ b/lib/vtls/schannel_int.h
@@ -24,7 +24,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SCHANNEL
 
diff --git a/lib/vtls/schannel_verify.c b/lib/vtls/schannel_verify.c
index a8c18ae2ac..b44b9e8ee3 100644
--- a/lib/vtls/schannel_verify.c
+++ b/lib/vtls/schannel_verify.c
@@ -29,7 +29,7 @@
  * only be invoked by code in schannel.c.
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SCHANNEL
 #ifndef USE_WINDOWS_SSPI
@@ -39,19 +39,19 @@
 #include "schannel.h"
 #include "schannel_int.h"
 
-#include "inet_pton.h"
+#include "../inet_pton.h"
 #include "vtls.h"
 #include "vtls_int.h"
-#include "sendf.h"
-#include "strerror.h"
-#include "curl_multibyte.h"
-#include "curl_printf.h"
+#include "../sendf.h"
+#include "../strerror.h"
+#include "../curl_multibyte.h"
+#include "../curl_printf.h"
 #include "hostcheck.h"
-#include "version_win32.h"
+#include "../version_win32.h"
 
 /* The last #include file should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #define BACKEND ((struct schannel_ssl_backend_data *)connssl->backend)
 
diff --git a/lib/vtls/sectransp.c b/lib/vtls/sectransp.c
index 24061a51e3..f0094df584 100644
--- a/lib/vtls/sectransp.c
+++ b/lib/vtls/sectransp.c
@@ -28,18 +28,18 @@
  * TLS/SSL layer. No code but vtls.c should ever call or use these functions.
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SECTRANSP
 
-#include "urldata.h" /* for the Curl_easy definition */
-#include "curl_base64.h"
-#include "strparse.h"
-#include "multiif.h"
-#include "strcase.h"
+#include "../urldata.h" /* for the Curl_easy definition */
+#include "../curl_base64.h"
+#include "../strparse.h"
+#include "../multiif.h"
+#include "../strcase.h"
 #include "x509asn1.h"
 #include "vtls_scache.h"
-#include "strerror.h"
+#include "../strerror.h"
 #include "cipher_suite.h"
 
 #ifdef __clang__
@@ -134,19 +134,19 @@
 #include <sys/sysctl.h>
 #endif /* CURL_BUILD_MAC */
 
-#include "sendf.h"
-#include "inet_pton.h"
-#include "connect.h"
-#include "select.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
+#include "../connect.h"
+#include "../select.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "sectransp.h"
-#include "curl_printf.h"
-#include "strdup.h"
+#include "../curl_printf.h"
+#include "../strdup.h"
 
-#include "curl_memory.h"
+#include "../curl_memory.h"
 /* The last #include file should be: */
-#include "memdebug.h"
+#include "../memdebug.h"
 
 
 /* From MacTypes.h (which we cannot include because it is not present in
diff --git a/lib/vtls/sectransp.h b/lib/vtls/sectransp.h
index 0f1085ad91..c82dc18445 100644
--- a/lib/vtls/sectransp.h
+++ b/lib/vtls/sectransp.h
@@ -24,7 +24,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SECTRANSP
 
diff --git a/lib/vtls/vtls.c b/lib/vtls/vtls.c
index 6da7554900..8893b1a0af 100644
--- a/lib/vtls/vtls.c
+++ b/lib/vtls/vtls.c
@@ -38,7 +38,7 @@
    https://httpd.apache.org/docs/2.0/ssl/ssl_intro.html
 */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
@@ -50,8 +50,8 @@
 #include <fcntl.h>
 #endif
 
-#include "urldata.h"
-#include "cfilters.h"
+#include "../urldata.h"
+#include "../cfilters.h"
 
 #include "vtls.h" /* generic SSL protos etc */
 #include "vtls_int.h"
@@ -66,28 +66,28 @@
 #include "bearssl.h"        /* BearSSL versions */
 #include "rustls.h"         /* Rustls versions */
 
-#include "slist.h"
-#include "sendf.h"
-#include "strcase.h"
-#include "url.h"
-#include "progress.h"
-#include "share.h"
-#include "multiif.h"
-#include "timeval.h"
-#include "curl_md5.h"
-#include "curl_sha256.h"
-#include "warnless.h"
-#include "curl_base64.h"
-#include "curl_printf.h"
-#include "inet_pton.h"
-#include "connect.h"
-#include "select.h"
-#include "strdup.h"
-#include "rand.h"
+#include "../slist.h"
+#include "../sendf.h"
+#include "../strcase.h"
+#include "../url.h"
+#include "../progress.h"
+#include "../share.h"
+#include "../multiif.h"
+#include "../timeval.h"
+#include "../curl_md5.h"
+#include "../curl_sha256.h"
+#include "../warnless.h"
+#include "../curl_base64.h"
+#include "../curl_printf.h"
+#include "../inet_pton.h"
+#include "../connect.h"
+#include "../select.h"
+#include "../strdup.h"
+#include "../rand.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 #define CLONE_STRING(var)                    \
diff --git a/lib/vtls/vtls.h b/lib/vtls/vtls.h
index b751c3743c..0302151bb5 100644
--- a/lib/vtls/vtls.h
+++ b/lib/vtls/vtls.h
@@ -23,7 +23,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 struct connectdata;
 struct ssl_config_data;
@@ -44,7 +44,7 @@ struct dynbuf;
 #define SSLSUPP_CIPHER_LIST  (1<<9) /* supports TLS 1.0-1.2 ciphersuites */
 
 #ifdef USE_ECH
-# include "curl_base64.h"
+# include "../curl_base64.h"
 # define ECH_ENABLED(__data__) \
     (__data__->set.tls_ech && \
      !(__data__->set.tls_ech & CURLECH_DISABLE)\
diff --git a/lib/vtls/vtls_int.h b/lib/vtls/vtls_int.h
index 5dadbb1f24..0632a07657 100644
--- a/lib/vtls/vtls_int.h
+++ b/lib/vtls/vtls_int.h
@@ -23,9 +23,9 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
-#include "cfilters.h"
-#include "urldata.h"
+#include "../curl_setup.h"
+#include "../cfilters.h"
+#include "../urldata.h"
 #include "vtls.h"
 
 #ifdef USE_SSL
diff --git a/lib/vtls/vtls_scache.c b/lib/vtls/vtls_scache.c
index ea80055ad6..2d8e30c41b 100644
--- a/lib/vtls/vtls_scache.c
+++ b/lib/vtls/vtls_scache.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SSL
 
@@ -36,28 +36,28 @@
 #include <fcntl.h>
 #endif
 
-#include "urldata.h"
-#include "cfilters.h"
+#include "../urldata.h"
+#include "../cfilters.h"
 
 #include "vtls.h" /* generic SSL protos etc */
 #include "vtls_int.h"
 #include "vtls_scache.h"
 #include "vtls_spack.h"
 
-#include "strcase.h"
-#include "url.h"
-#include "llist.h"
-#include "share.h"
-#include "curl_trc.h"
-#include "curl_sha256.h"
-#include "rand.h"
-#include "warnless.h"
-#include "curl_printf.h"
-#include "strdup.h"
+#include "../strcase.h"
+#include "../url.h"
+#include "../llist.h"
+#include "../share.h"
+#include "../curl_trc.h"
+#include "../curl_sha256.h"
+#include "../rand.h"
+#include "../warnless.h"
+#include "../curl_printf.h"
+#include "../strdup.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 
 static bool cf_ssl_peer_key_is_global(const char *peer_key);
diff --git a/lib/vtls/vtls_scache.h b/lib/vtls/vtls_scache.h
index 8ef6eecba7..c95fa42af1 100644
--- a/lib/vtls/vtls_scache.h
+++ b/lib/vtls/vtls_scache.h
@@ -23,9 +23,9 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
-#include "cfilters.h"
-#include "urldata.h"
+#include "../curl_setup.h"
+#include "../cfilters.h"
+#include "../urldata.h"
 
 #ifdef USE_SSL
 
diff --git a/lib/vtls/vtls_spack.c b/lib/vtls/vtls_spack.c
index 8fe9c151f1..e49be6d6b2 100644
--- a/lib/vtls/vtls_spack.c
+++ b/lib/vtls/vtls_spack.c
@@ -22,19 +22,19 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SSLS_EXPORT
 
-#include "urldata.h"
-#include "curl_trc.h"
+#include "../urldata.h"
+#include "../curl_trc.h"
 #include "vtls_scache.h"
 #include "vtls_spack.h"
-#include "strdup.h"
+#include "../strdup.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #ifdef _MSC_VER
 #if _MSC_VER >= 1600
diff --git a/lib/vtls/vtls_spack.h b/lib/vtls/vtls_spack.h
index 98699456a5..4cdabae30e 100644
--- a/lib/vtls/vtls_spack.h
+++ b/lib/vtls/vtls_spack.h
@@ -23,7 +23,7 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_SSLS_EXPORT
 
diff --git a/lib/vtls/wolfssl.c b/lib/vtls/wolfssl.c
index a7ea34aa68..5550dfb1f3 100644
--- a/lib/vtls/wolfssl.c
+++ b/lib/vtls/wolfssl.c
@@ -28,7 +28,7 @@
  *
  */
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_WOLFSSL
 
@@ -56,30 +56,30 @@
 
 #include <limits.h>
 
-#include "urldata.h"
-#include "sendf.h"
-#include "inet_pton.h"
+#include "../urldata.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
 #include "keylog.h"
-#include "parsedate.h"
-#include "connect.h" /* for the connect timeout */
-#include "progress.h"
-#include "select.h"
-#include "strcase.h"
-#include "strdup.h"
+#include "../parsedate.h"
+#include "../connect.h" /* for the connect timeout */
+#include "../progress.h"
+#include "../select.h"
+#include "../strcase.h"
+#include "../strdup.h"
 #include "x509asn1.h"
-#include "curl_printf.h"
-#include "multiif.h"
+#include "../curl_printf.h"
+#include "../multiif.h"
 
 #include <wolfssl/ssl.h>
 #include <wolfssl/error-ssl.h>
 #include "wolfssl.h"
 
 /* The last #include files should be: */
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 #ifdef HAVE_WOLFSSL_CTX_GENERATEECHCONFIG
 #define USE_ECH_WOLFSSL
diff --git a/lib/vtls/wolfssl.h b/lib/vtls/wolfssl.h
index dfb951b693..c741f01bd9 100644
--- a/lib/vtls/wolfssl.h
+++ b/lib/vtls/wolfssl.h
@@ -23,11 +23,11 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #ifdef USE_WOLFSSL
 
-#include "urldata.h"
+#include "../urldata.h"
 
 struct alpn_spec;
 struct ssl_peer;
diff --git a/lib/vtls/x509asn1.c b/lib/vtls/x509asn1.c
index 1d272c04e7..09951529f7 100644
--- a/lib/vtls/x509asn1.c
+++ b/lib/vtls/x509asn1.c
@@ -22,7 +22,7 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_GNUTLS) || defined(USE_WOLFSSL) ||      \
   defined(USE_SCHANNEL) || defined(USE_SECTRANSP) ||    \
@@ -39,22 +39,22 @@
 #endif
 
 #include <curl/curl.h>
-#include "urldata.h"
-#include "strcase.h"
-#include "curl_ctype.h"
+#include "../urldata.h"
+#include "../strcase.h"
+#include "../curl_ctype.h"
 #include "hostcheck.h"
-#include "vtls/vtls.h"
-#include "vtls/vtls_int.h"
-#include "sendf.h"
-#include "inet_pton.h"
-#include "curl_base64.h"
+#include "vtls.h"
+#include "vtls_int.h"
+#include "../sendf.h"
+#include "../inet_pton.h"
+#include "../curl_base64.h"
 #include "x509asn1.h"
-#include "dynbuf.h"
+#include "../dynbuf.h"
 
 /* The last 3 #include files should be in this order */
-#include "curl_printf.h"
-#include "curl_memory.h"
-#include "memdebug.h"
+#include "../curl_printf.h"
+#include "../curl_memory.h"
+#include "../memdebug.h"
 
 /*
  * Constants.
diff --git a/lib/vtls/x509asn1.h b/lib/vtls/x509asn1.h
index e1abff06c8..ef2e8c369c 100644
--- a/lib/vtls/x509asn1.h
+++ b/lib/vtls/x509asn1.h
@@ -25,14 +25,14 @@
  *
  ***************************************************************************/
 
-#include "curl_setup.h"
+#include "../curl_setup.h"
 
 #if defined(USE_GNUTLS) || defined(USE_WOLFSSL) || \
   defined(USE_SCHANNEL) || defined(USE_SECTRANSP) || \
   defined(USE_MBEDTLS) || defined(USE_RUSTLS)
 
-#include "cfilters.h"
-#include "urldata.h"
+#include "../cfilters.h"
+#include "../urldata.h"
 
 /*
  * Types.
diff --git a/scripts/mk-unity.pl b/scripts/mk-unity.pl
index f9ebf2524c..4ad86d1c77 100755
--- a/scripts/mk-unity.pl
+++ b/scripts/mk-unity.pl
@@ -35,6 +35,8 @@ if(!@ARGV) {
     die "Usage: $0 [<c-sources>] [--exclude <exclude-c-sources>]\n";
 }
 
+my $srcdir = shift @ARGV;
+
 # Specific sources to exclude or add as an extra source file
 my @src;
 my %exclude;
@@ -58,6 +60,11 @@ HEADER
 
 foreach my $src (@src) {
     if($src =~ /\.c$/g && !exists $exclude{$src}) {
-        print "#include \"$src\"\n";
+        if(-e "$srcdir/$src") {
+            print "#include \"$srcdir/$src\"\n";
+        }
+        else {
+            print "#include \"$src\"\n";
+        }
     }
 }
diff --git a/src/Makefile.am b/src/Makefile.am
index dc431e1395..f6df54ef76 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -121,7 +121,7 @@ endif
 # Use absolute directory to disable VPATH
 ASCIIPAGE=$(top_builddir)/docs/cmdline-opts/curl.txt
 MKHELP=$(top_srcdir)/src/mkhelp.pl
-HUGE=tool_hugehelp.c
+HUGE=$(builddir)/tool_hugehelp.c
 
 HUGECMD = $(HUGEIT_$(V))
 HUGEIT_0 = @echo "  HUGE    " $@;
@@ -164,7 +164,7 @@ curl_cfiles_gen += $(HUGE)
 curl_hfiles_gen += tool_hugehelp.h
 CLEANFILES += $(HUGE)
 
-CA_EMBED_CSOURCE = tool_ca_embed.c
+CA_EMBED_CSOURCE = $(builddir)/tool_ca_embed.c
 curl_cfiles_gen += $(CA_EMBED_CSOURCE)
 CLEANFILES += $(CA_EMBED_CSOURCE)
 if CURL_CA_EMBED_SET
@@ -184,12 +184,7 @@ CS_ = $(CS_0)
 
 # ignore generated C files since they play by slightly different rules!
 checksrc:
-	$(CHECKSRC)(@PERL@ $(top_srcdir)/scripts/checksrc.pl -D$(srcdir) \
-	  -W$(srcdir)/$(HUGE) \
-	  -W$(srcdir)/$(CA_EMBED_CSOURCE) \
-	  -W$(srcdir)/curltool_unity.c \
-	  -W$(srcdir)/libcurltool_unity.c \
-	  $(srcdir)/*.[ch])
+	$(CHECKSRC)(@PERL@ $(top_srcdir)/scripts/checksrc.pl -D$(srcdir) $(CURL_CFILES) $(CURL_HFILES))
 
 if DEBUGBUILD
 # for debug builds, we scan the sources on all regular make invokes