diff --git a/mm/util.c b/mm/util.c
index ab1424d..c4eb439 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -210,7 +210,7 @@ char *strndup_user(const char __user *s, long n)
 
 	length = strnlen_user(s, n);
 
-	if (!length)
+	if (length < 1)
 		return ERR_PTR(-EFAULT);
 
 	if (length > n)