--- a/demos/programs/workspace/xrmLib.c
+++ b/demos/programs/workspace/xrmLib.c
@@ -30,7 +30,14 @@ static char rcsid[] = "$XConsortium: xrmLib.c /main/6 1995/07/14 10:01:41 drk $"
 #endif
 
 #include <stdio.h>
-#include <malloc.h>
+#if defined(__cplusplus) || defined(__STDC__) || defined(__EXTENSIONS__)
+#  include <stdlib.h>
+#  if defined(HAVE_MALLOC_H)
+#  include <malloc.h>
+#  elif defined(HAVE_SYS_MALLOC_H)
+#  include <sys/malloc.h>
+#  endif
+#endif
 #include <Xm/Xm.h>
 #include "wsm.h"
 #include "wsmDebug.h"