diff --git a/src/gc/mark_sweep.h b/src/gc/mark_sweep.h
index 76c5428..ed74f99 100644
--- a/src/gc/mark_sweep.h
+++ b/src/gc/mark_sweep.h
@@ -52,6 +52,9 @@
       EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  void MarkConcurrentRoots();
+      EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);
+
   // Verify that image roots point to only marked objects within the alloc space.
   void VerifyImageRoots() EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);