diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index 1d9558cc..5f6468e7 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -427,6 +427,10 @@ void gc_wait_handshake();
 void gc_start_collector();
 void gc_mutator_thread_blocked(gc_thread_data *thd, object cont);
 void gc_mutator_thread_runnable(gc_thread_data *thd, object result);
+#define set_thread_blocked(d, c) \
+  gc_mutator_thread_blocked(((gc_thread_data *)d), (r))
+#define return_runnable(d, r) \
+  gc_mutator_thread_runnable(((gc_thread_data *)d), (r))
 gc_heap *gc_get_heap();
 int gc_minor(void *data, object low_limit, object high_limit, closure cont, object *args, int num_args);
 /* Mutation table to support minor GC write barrier */