diff --git a/vlib/sync/sync_darwin.c.v b/vlib/sync/sync_darwin.c.v
index dde745f3e6..85ab6425f8 100644
--- a/vlib/sync/sync_darwin.c.v
+++ b/vlib/sync/sync_darwin.c.v
@@ -33,6 +33,9 @@ fn C.pthread_cond_destroy(voidptr) int
 [typedef]
 struct C.pthread_mutex_t {}
 
+[typedef]
+struct C.pthread_cond_t {}
+
 [typedef]
 struct C.pthread_rwlock_t {}