diff --git a/tests/libtest/lib1960.c b/tests/libtest/lib1960.c
index 4fb7247073..cfbff3407f 100644
--- a/tests/libtest/lib1960.c
+++ b/tests/libtest/lib1960.c
@@ -25,6 +25,8 @@
 
 #ifdef HAVE_INET_PTON
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
@@ -32,6 +34,7 @@
 #include <arpa/inet.h>
 #endif
 
+#include "curl_memory.h"
 #include "memdebug.h"
 
 /* to prevent libcurl from closing our socket */
diff --git a/tests/libtest/lib571.c b/tests/libtest/lib571.c
index 4a8d805bf0..86e242a9a3 100644
--- a/tests/libtest/lib571.c
+++ b/tests/libtest/lib571.c
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "first.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
@@ -34,6 +36,8 @@
 #endif
 
 #include "testutil.h"
+
+#include "curl_memory.h"
 #include "memdebug.h"
 
 #define RTP_PKT_CHANNEL(p)   ((int)((unsigned char)((p)[1])))
diff --git a/tests/tunit/tool1621.c b/tests/tunit/tool1621.c
index 4919988c6c..571a33c43f 100644
--- a/tests/tunit/tool1621.c
+++ b/tests/tunit/tool1621.c
@@ -23,8 +23,8 @@
  ***************************************************************************/
 #include "unitcheck.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
 #include "tool_xattr.h"
-
 #include "memdebug.h" /* LAST include file */
 
 static CURLcode test_tool1621(char *arg)
diff --git a/tests/unit/unit1305.c b/tests/unit/unit1305.c
index 025b2321be..bb172f8c6e 100644
--- a/tests/unit/unit1305.c
+++ b/tests/unit/unit1305.c
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "unitcheck.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
diff --git a/tests/unit/unit1663.c b/tests/unit/unit1663.c
index b017965380..c4990f4e19 100644
--- a/tests/unit/unit1663.c
+++ b/tests/unit/unit1663.c
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "unitcheck.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
diff --git a/tests/unit/unit1664.c b/tests/unit/unit1664.c
index d3e7670108..0240c08a65 100644
--- a/tests/unit/unit1664.c
+++ b/tests/unit/unit1664.c
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "unitcheck.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
diff --git a/tests/unit/unit2600.c b/tests/unit/unit2600.c
index 21e575258b..de8888726f 100644
--- a/tests/unit/unit2600.c
+++ b/tests/unit/unit2600.c
@@ -23,6 +23,8 @@
  ***************************************************************************/
 #include "unitcheck.h"
 
+#include "curl_mem_undef.h" /* include BEFORE system headers */
+
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif