diff --git a/libkern/string.c b/libkern/string.c
index cfb698da..6fba888a 100644
--- a/libkern/string.c
+++ b/libkern/string.c
@@ -69,6 +69,9 @@ char* strncpy(char *dest, const char *src, size_t n)
 {
 	size_t i;
 
+	if (BUILTIN_EXPECT(!dest || !src, 0))
+		return dest;
+
 	for (i = 0 ; i < n && src[i] != '\0' ; i++)
 		dest[i] = src[i];
 	if (i < n)
@@ -85,6 +88,9 @@ char* strcpy(char *dest, const char *src)
 {
         size_t i;
 
+	if (BUILTIN_EXPECT(!dest || !src, 0))
+		return dest;
+
         for (i = 0 ; src[i] != '\0' ; i++)
                 dest[i] = src[i];
         dest[i] = '\0';