diff --git a/lib/string.c b/lib/string.c
index 5c8b55af0df..d886ef157c1 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -86,6 +86,10 @@ EXPORT_SYMBOL(strcpy);
  *
  * The result is not %NUL-terminated if the source exceeds
  * @count bytes.
+ *
+ * In the case where the length of @src is less than  that  of
+ * count, the remainder of @dest will be padded with %NUL.
+ *
  */
 char * strncpy(char * dest,const char *src,size_t count)
 {