diff --git a/config.h.in b/config.h.in
index 9e8f9911b..c1323a88e 100644
--- a/config.h.in
+++ b/config.h.in
@@ -9,6 +9,10 @@
 #define GCRYPT_NO_DEPRECATED 1
 #define HAVE_MEMMOVE 1
 
+#if @MM_DEBUG@
+#define MM_DEBUG @MM_DEBUG@
+#endif
+
 /* Define to 1 to enable disk cache statistics.  */
 #define DISK_CACHE_STATS @DISK_CACHE_STATS@
 #define BOOT_TIME_STATS @BOOT_TIME_STATS@
diff --git a/configure.ac b/configure.ac
index d1eaafee1..50f7bc6a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1519,9 +1519,11 @@ AC_ARG_ENABLE([mm-debug],
 	      AS_HELP_STRING([--enable-mm-debug],
                              [include memory manager debugging]))
 if test x$enable_mm_debug = xyes; then
-    AC_DEFINE([MM_DEBUG], [1],
-            [Define to 1 if you enable memory manager debugging.])
+    MM_DEBUG=1
+else
+    MM_DEBUG=0
 fi
+AC_SUBST([MM_DEBUG])
 
 AC_ARG_ENABLE([cache-stats],
 	      AS_HELP_STRING([--enable-cache-stats],