diff --git a/runtime/gc/reference_queue.h b/runtime/gc/reference_queue.h
index b73a880..c48d48c 100644
--- a/runtime/gc/reference_queue.h
+++ b/runtime/gc/reference_queue.h
@@ -27,7 +27,6 @@
 #include "globals.h"
 #include "jni.h"
 #include "obj_ptr.h"
-#include "object_callbacks.h"
 #include "offsets.h"
 #include "thread_pool.h"
 
@@ -36,6 +35,9 @@
 class Reference;
 }  // namespace mirror
 
+class IsMarkedVisitor;
+class MarkObjectVisitor;
+
 namespace gc {
 
 namespace collector {