diff --git a/configure.ac b/configure.ac
index f6b4f6a53..07e4d2a2b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -166,18 +166,6 @@ AC_DEFINE(FVWM2RC, ".fvwm2rc")
 
 # Various configure-time options
 
-AC_ARG_ENABLE(dmalloc,
-  AS_HELP_STRING([--enable-dmalloc],
-    [enable support for the dmalloc debugging library]),
-  [ac_cv_dmalloc="$enableval"],
-  [ac_cv_dmalloc="no"])
-
-AC_ARG_ENABLE(efence,
-  AS_HELP_STRING([--enable-efence],
-    [enable support for the efence debugging library]),
-  [ac_cv_efence="$enableval"],
-  [ac_cv_efence="no"])
-
 dnl dummy: smr_SWITCH(sm, dummy for test script, on, SESSION)
 
 # Need to know where X is, for finding some libraries (e.g. xpm)
@@ -1278,19 +1266,6 @@ AH_VERBATIM([_COMPAT_OLD_KEYSYMDEF],
 #  define XK_Page_Down XK_Next
 #endif])
 
-# Allow building with dmalloc.  Do this last to avoid screwing up any
-# other checks above.
-case "$ac_cv_dmalloc" in
-  yes) AC_CHECK_HEADERS(dmalloc.h)
-       AC_CHECK_LIB(dmalloc, dmalloc_shutdown)
-       CPPFLAGS="$CPPFLAGS -DDMALLOC_FUNC_CHECK" ;;
-esac
-
-
-# Allow building with efence.
-case "$ac_cv_efence" in
-  yes) AC_CHECK_LIB(efence, malloc) ;;
-esac
 
 # some explicit definitions for config.h file
 AH_VERBATIM([_ZEND_EXPLICIT_DEFINITIONS],
@@ -1562,9 +1537,3 @@ Fvwm3 Configuration:
   Build man pages?                    $with_mandoc$problem_mandoc
 
 "
-case "$ac_cv_dmalloc" in
-  yes) echo "  DMALLOC heap debugging library enabled." ;;
-esac
-case "$ac_cv_efence" in
-  yes) echo "  EFENCE debugging library enabled." ;;
-esac
diff --git a/libs/fvwmlib.h b/libs/fvwmlib.h
index 7217c7a51..36fee51ce 100644
--- a/libs/fvwmlib.h
+++ b/libs/fvwmlib.h
@@ -12,11 +12,6 @@
 /* Convenience function ti init all the graphics subsystems */
 void flib_init_graphics(Display *dpy);
 
-/* Set up heap debugging library dmalloc.  */
-#ifdef HAVE_DMALLOC_H
-#include <dmalloc.h>
-#endif
-
 /* Set up mtrace from glibc 2.1.x for x > ?  */
 #ifdef MTRACE_DEBUGGING
 #include <mcheck.h>
diff --git a/modules/FvwmIconMan/FvwmIconMan.c b/modules/FvwmIconMan/FvwmIconMan.c
index 4f0e1c328..b9b93b5e4 100644
--- a/modules/FvwmIconMan/FvwmIconMan.c
+++ b/modules/FvwmIconMan/FvwmIconMan.c
@@ -206,13 +206,6 @@ main(int argc, char **argv)
 {
 	int i;
 
-#ifdef HAVE_LIBEFENCE
-	extern int EF_PROTECT_BELOW, EF_PROTECT_FREE;
-
-	EF_PROTECT_BELOW = 1;
-	EF_PROTECT_FREE = 1;
-#endif
-
 	FlocaleInit(LC_CTYPE, "", "", "FvwmIconMan");
 
 	OpenConsole(OUTPUT_FILE);
diff --git a/modules/FvwmIconMan/FvwmIconMan.h b/modules/FvwmIconMan/FvwmIconMan.h
index 29a6e428a..dd7be1466 100644
--- a/modules/FvwmIconMan/FvwmIconMan.h
+++ b/modules/FvwmIconMan/FvwmIconMan.h
@@ -43,10 +43,6 @@ struct malloc_header {
 
 #endif
 
-#ifdef HAVE_DMALLOC_H
-#include <dmalloc.h>
-#endif
-
 extern void PrintMemuse(void);
 
 typedef unsigned long Ulong;