--- a/dmalloc.h.3
+++ b/dmalloc.h.3
@@ -405,6 +405,7 @@
  *
  * string -> String we are duplicating.
  */
+#undef strdup
 extern
 char	*strdup(const char *string);
 #endif /* ifndef DMALLOC_STRDUP_MACRO */
@@ -429,6 +430,7 @@
  *
  * len -> Length of the string to duplicate.
  */
+#undef strndup
 extern
 char	*strndup(const char *string, const DMALLOC_SIZE len);
 
