diff --git a/Source/synchronization.m b/Source/synchronization.m
index 697a975ea..cce854370 100644
--- a/Source/synchronization.m
+++ b/Source/synchronization.m
@@ -161,6 +161,7 @@ sync_add_node(id obj)
  * Add a lock for the object.
  */ 
 int
+__attribute__((weak))
 objc_sync_enter(id obj)
 {
   lock_node_t *node = NULL;
@@ -202,6 +203,7 @@ objc_sync_enter(id obj)
  * Remove a lock for the object.
  */
 int
+__attribute__((weak))
 objc_sync_exit(id obj)
 {
   lock_node_t *node = NULL;