diff --git a/lib/btree.c b/lib/btree.c
index 5cf9e74ec3f32a9f0d7fbb247b79f0815ce981b6..f9a484676cb6a8e4782333ce164bf0662b583b78 100644
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -509,6 +509,7 @@ static int btree_insert_level(struct btree_head *head, struct btree_geo *geo,
 int btree_insert(struct btree_head *head, struct btree_geo *geo,
 		unsigned long *key, void *val, gfp_t gfp)
 {
+	BUG_ON(!val);
 	return btree_insert_level(head, geo, key, val, 1, gfp);
 }
 EXPORT_SYMBOL_GPL(btree_insert);