diff --git a/include/QF/zone.h b/include/QF/zone.h
index da174cfec..0e3ec6ef2 100644
--- a/include/QF/zone.h
+++ b/include/QF/zone.h
@@ -150,6 +150,7 @@ void Cache_Remove (cache_user_t *c);
 void *Cache_Get (cache_user_t *c);
 void *Cache_TryGet (cache_user_t *c);
 void Cache_Release (cache_user_t *c);
+int Cache_ReadLock (cache_user_t *c);
 
 /* Flags */
 #define QA_NONE			0
diff --git a/libs/util/zone.c b/libs/util/zone.c
index 65b3b5ed9..bd7ae650b 100644
--- a/libs/util/zone.c
+++ b/libs/util/zone.c
@@ -1077,6 +1077,12 @@ Cache_Release (cache_user_t *c)
 	CACHE_WRITE_UNLOCK;
 }
 
+int
+Cache_ReadLock (cache_user_t *c)
+{
+	return (((cache_system_t *)c->data) - 1)->readlock;
+}
+
 // QA_alloc and friends =======================================================
 
 size_t (*QA_alloc_callback) (size_t size);