diff --git a/src/heap.cc b/src/heap.cc
index 5a19d28..b12ff2d 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -249,8 +249,6 @@
   // make it clear that you can't use locks during heap initialization.
   lock_ = new Mutex("Heap lock", kHeapLock);
 
-  Heap::EnableObjectValidation();
-
   if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) {
     LOG(INFO) << "Heap() exiting";
   }
@@ -318,7 +316,8 @@
 
 #if VERIFY_OBJECT_ENABLED
 void Heap::VerifyObject(const Object* obj) {
-  if (!verify_objects_) {
+  if (this == NULL || !verify_objects_ || Runtime::Current()->IsShuttingDown() ||
+      Runtime::Current()->GetThreadList()->GetLockOwner() == Thread::Current()->GetTid()) {
     return;
   }
   ScopedHeapLock heap_lock;
diff --git a/src/heap.h b/src/heap.h
index be8c62a..7717871 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -243,6 +243,8 @@
 
   void VerifyObjectLocked(const Object *obj);
 
+  void VerifyHeapLocked();
+
   static void VerificationCallback(Object* obj, void* arg);
 
   Mutex* lock_;
diff --git a/src/heap_bitmap.cc b/src/heap_bitmap.cc
index 21db0e6..d432fa9 100644
--- a/src/heap_bitmap.cc
+++ b/src/heap_bitmap.cc
@@ -87,6 +87,9 @@
 void HeapBitmap::Walk(HeapBitmap::Callback* callback, void* arg) {
   CHECK(bitmap_begin_ != NULL);
   CHECK(callback != NULL);
+  if (heap_end_ < heap_begin_) {
+    return;  // Bitmap is empty.
+  }
   uintptr_t end = HB_OFFSET_TO_INDEX(heap_end_ - heap_begin_);
   for (uintptr_t i = 0; i <= end; ++i) {
     word w = bitmap_begin_[i];
diff --git a/src/runtime.cc b/src/runtime.cc
index b340317..1378229 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -642,6 +642,7 @@
                    options->heap_growth_limit_,
                    options->heap_maximum_size_,
                    options->image_);
+  heap_->EnableObjectValidation();
 
   BlockSignals();
 
diff --git a/src/runtime_support.cc b/src/runtime_support.cc
index af8ce22..e76e89f 100644
--- a/src/runtime_support.cc
+++ b/src/runtime_support.cc
@@ -34,6 +34,7 @@
   // Be aware the store below may well stomp on an incoming argument
   *sp = Runtime::Current()->GetCalleeSaveMethod(type);
   self->SetTopOfStack(sp, 0);
+  self->VerifyStack();
 }
 
 /*
diff --git a/src/scoped_jni_thread_state.h b/src/scoped_jni_thread_state.h
index 2db04fc..552f5ed 100644
--- a/src/scoped_jni_thread_state.h
+++ b/src/scoped_jni_thread_state.h
@@ -29,6 +29,7 @@
       : env_(reinterpret_cast<JNIEnvExt*>(env)) {
     self_ = ThreadForEnv(env);
     old_thread_state_ = self_->SetState(Thread::kRunnable);
+    self_->VerifyStack();
   }
 
   ~ScopedJniThreadState() {
diff --git a/src/thread.cc b/src/thread.cc
index 353f94d..f15bfd5 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -1637,7 +1637,7 @@
   bool VisitFrame(const Frame& frame, uintptr_t pc) {
     Method* m = frame.GetMethod();
     if (false) {
-      LOG(INFO) << "Visiting stack roots in " << PrettyMethod(m, false)
+      LOG(INFO) << "Visiting stack roots in " << PrettyMethod(m)
                 << StringPrintf("@ PC:%04x", m->ToDexPC(pc));
     }
     // Process register map (which native and callee save methods don't have)
@@ -1728,6 +1728,18 @@
   WalkStack(&mapper);
 }
 
+#if VERIFY_OBJECT_ENABLED
+void VerifyObject(const Object* obj, void*) {
+  Runtime::Current()->GetHeap()->VerifyObject(obj);
+}
+
+void Thread::VerifyStack() {
+  Context* context = GetLongJumpContext();
+  ReferenceMapVisitor mapper(context, VerifyObject, NULL);
+  WalkStack(&mapper);
+}
+#endif
+
 static const char* kStateNames[] = {
   "Terminated",
   "Runnable",
diff --git a/src/thread.h b/src/thread.h
index c35d26a..d764ff3 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -324,6 +324,12 @@
 
   void VisitRoots(Heap::RootVisitor* visitor, void* arg);
 
+#if VERIFY_OBJECT_ENABLED
+  void VerifyStack();
+#else
+  void VerifyStack() {}
+#endif
+
   //
   // Offsets of various members of native Thread class, used by compiled code.
   //