diff --git a/lib/string.c b/lib/string.c
index 4288e0158d47..7548eb715ddb 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -85,7 +85,6 @@ EXPORT_SYMBOL(strcasecmp);
  * @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;
@@ -302,7 +301,6 @@ EXPORT_SYMBOL(stpcpy);
  * @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;
@@ -378,7 +376,6 @@ EXPORT_SYMBOL(strlcat);
  * @cs: One string
  * @ct: Another string
  */
-#undef strcmp
 int strcmp(const char *cs, const char *ct)
 {
 	unsigned char c1, c2;
@@ -958,7 +955,6 @@ EXPORT_SYMBOL(memcmp);
  * while this particular implementation is a simple (tail) call to memcmp, do
  * not rely on anything but whether the return value is zero or non-zero.
  */
-#undef bcmp
 int bcmp(const void *a, const void *b, size_t len)
 {
 	return memcmp(a, b, len);