diff --git a/runtime/stack.cc b/runtime/stack.cc
index 2ea3949..6466efd 100644
--- a/runtime/stack.cc
+++ b/runtime/stack.cc
@@ -112,7 +112,7 @@
 extern "C" mirror::Object* artQuickGetProxyThisObject(ArtMethod** sp)
     REQUIRES_SHARED(Locks::mutator_lock_);
 
-mirror::Object* StackVisitor::GetThisObject() const {
+ObjPtr<mirror::Object> StackVisitor::GetThisObject() const {
   DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
   ArtMethod* m = GetMethod();
   if (m->IsStatic()) {