diff --git a/lib/string.c b/lib/string.c
index 4bb93ad..5c8b55a 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -65,6 +65,7 @@
  * @dest: Where to copy the string to
  * @src: Where to copy the string from
  */
+#undef strcpy
 char * strcpy(char * dest,const char *src)
 {
 	char *tmp = dest;
@@ -132,6 +133,7 @@
  * @dest: The string to be appended to
  * @src: The string to append to it
  */
+#undef strcat
 char * strcat(char * dest, const char * src)
 {
 	char *tmp = dest;
@@ -209,6 +211,7 @@
  * @cs: One string
  * @ct: Another string
  */
+#undef strcmp
 int strcmp(const char * cs,const char * ct)
 {
 	register signed char __res;
@@ -514,6 +517,7 @@
  * @ct: Another area of memory
  * @count: The size of the area.
  */
+#undef memcmp
 int memcmp(const void * cs,const void * ct,size_t count)
 {
 	const unsigned char *su1, *su2;