diff --git a/lib/getdate.y b/lib/getdate.y
index 0bf30c43bac836e984ff1c3948b37eb92367f9d2..50f84390b554d6459e68ae161ea00d52afdb0caf 100644
--- a/lib/getdate.y
+++ b/lib/getdate.y
@@ -80,6 +80,11 @@
 # include <string.h>
 #endif
 
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
 # define __attribute__(x)
 #endif
diff --git a/lib/getpass.c b/lib/getpass.c
index d9d19322ccb3e32a648f8a9dfa2ff99242a1263f..7477742e0656cf7e882452cc140ca6d897ef2a27 100644
--- a/lib/getpass.c
+++ b/lib/getpass.c
@@ -66,6 +66,11 @@
 #  endif
 #endif
 
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
 /* no perror? make an fprintf! */
 #ifndef HAVE_PERROR
 #  define perror(x) fprintf(stderr, "Error in: %s\n", x)
diff --git a/lib/if2ip.c b/lib/if2ip.c
index 87ead2b9e1b066cc7b432237c61a62df98a23069..0acc3d6c8596222436103c83f4e8d573517852a2 100644
--- a/lib/if2ip.c
+++ b/lib/if2ip.c
@@ -70,6 +70,11 @@
 #include "inet_ntoa_r.h"
 #endif
 
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
 #define SYS_ERROR -1
 
 char *Curl_if2ip(char *interface, char *buf, int buf_size)
diff --git a/lib/netrc.c b/lib/netrc.c
index 2911af53edaa421fd9c2daa440dd465db5c2bf6f..6a712d4fd2b64470488b52ea0d7f5ac2ac6bd79e 100644
--- a/lib/netrc.c
+++ b/lib/netrc.c
@@ -42,6 +42,11 @@
 
 #include "strequal.h"
 
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
 /* Debug this single source file with:
    'make netrc' then run './netrc'!
 
diff --git a/lib/telnet.c b/lib/telnet.c
index c1b0601cc31f771adc7c18dd0a7acf877f0abf99..2b37d1755efc34a290dc8e2ee86b05bcc64e8c3d 100644
--- a/lib/telnet.c
+++ b/lib/telnet.c
@@ -82,6 +82,11 @@
 
 #include "arpa_telnet.h"
 
+/* The last #include file should be: */
+#ifdef MALLOCDEBUG
+#include "memdebug.h"
+#endif
+
 #define SUBBUFSIZE 512
 
 #define  SB_CLEAR(x)  x->subpointer = x->subbuffer;