diff --git a/lib/vauth/krb5_sspi.c b/lib/vauth/krb5_sspi.c
index 7317af809a..21636d59ee 100644
--- a/lib/vauth/krb5_sspi.c
+++ b/lib/vauth/krb5_sspi.c
@@ -32,7 +32,6 @@
 
 #include "vauth.h"
 #include "../curlx/warnless.h"
-#include "../curlx/multibyte.h"
 #include "../sendf.h"
 
 /*
diff --git a/lib/vauth/ntlm.c b/lib/vauth/ntlm.c
index e47135337a..22d028e8c2 100644
--- a/lib/vauth/ntlm.c
+++ b/lib/vauth/ntlm.c
@@ -39,7 +39,6 @@
 #include "../sendf.h"
 #include "../curl_ntlm_core.h"
 #include "../curl_gethostname.h"
-#include "../curlx/multibyte.h"
 #include "../curlx/warnless.h"
 #include "../rand.h"
 #include "../vtls/vtls.h"
diff --git a/lib/vauth/ntlm_sspi.c b/lib/vauth/ntlm_sspi.c
index 561de27dc3..d724907db6 100644
--- a/lib/vauth/ntlm_sspi.c
+++ b/lib/vauth/ntlm_sspi.c
@@ -31,7 +31,6 @@
 #include "vauth.h"
 #include "../curl_ntlm_core.h"
 #include "../curlx/warnless.h"
-#include "../curlx/multibyte.h"
 #include "../sendf.h"
 #include "../strdup.h"
 
diff --git a/lib/vauth/spnego_gssapi.c b/lib/vauth/spnego_gssapi.c
index 3a24e8860a..2feafdda4b 100644
--- a/lib/vauth/spnego_gssapi.c
+++ b/lib/vauth/spnego_gssapi.c
@@ -34,7 +34,6 @@
 #include "../curlx/base64.h"
 #include "../curl_gssapi.h"
 #include "../curlx/warnless.h"
-#include "../curlx/multibyte.h"
 #include "../sendf.h"
 
 #if defined(__GNUC__) && defined(__APPLE__)
diff --git a/lib/vauth/spnego_sspi.c b/lib/vauth/spnego_sspi.c
index 2a6548b6d4..31747c0a0e 100644
--- a/lib/vauth/spnego_sspi.c
+++ b/lib/vauth/spnego_sspi.c
@@ -33,7 +33,6 @@
 #include "vauth.h"
 #include "../curlx/base64.h"
 #include "../curlx/warnless.h"
-#include "../curlx/multibyte.h"
 #include "../sendf.h"
 #include "../strerror.h"