diff --git a/mm/slub.c b/mm/slub.c
index 4a8585b..9d52cce 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1979,7 +1979,7 @@
 {
 	int index = kmalloc_index(size);
 
-	if (!size)
+	if (!index)
 		return NULL;
 
 	/* Allocation too large? */