diff --git a/security/keys/internal.h b/security/keys/internal.h
index b47cc53..e66a16c 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -127,6 +127,8 @@
 	struct timespec		now;
 };
 
+extern int key_default_cmp(const struct key *key,
+			   const struct key_match_data *match_data);
 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 				    struct keyring_search_context *ctx);