diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index 91aba26..6d49d75 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -30,6 +30,7 @@
 #include "disassembler.h"
 #include "disasm.h"
 #include "jsregexp.h"
+#include "objects-visiting.h"
 
 namespace v8 {
 namespace internal {
@@ -648,6 +649,17 @@
 }
 
 
+void Map::NormalizedMapVerify() {
+  MapVerify();
+  ASSERT_EQ(Heap::empty_descriptor_array(), instance_descriptors());
+  ASSERT_EQ(Heap::empty_fixed_array(), code_cache());
+  ASSERT_EQ(0, pre_allocated_property_fields());
+  ASSERT_EQ(0, unused_property_fields());
+  ASSERT_EQ(StaticVisitorBase::GetVisitorId(instance_type(), instance_size()),
+      visitor_id());
+}
+
+
 void CodeCache::CodeCachePrint() {
   HeapObject::PrintHeader("CodeCache");
   PrintF("\n - default_cache: ");
@@ -1363,6 +1375,21 @@
 }
 
 
+void NormalizedMapCache::NormalizedMapCacheVerify() {
+  FixedArray::cast(this)->Verify();
+  if (FLAG_enable_slow_asserts) {
+    for (int i = 0; i < length(); i++) {
+      Object* e = get(i);
+      if (e->IsMap()) {
+        Map::cast(e)->NormalizedMapVerify();
+      } else {
+        ASSERT(e->IsUndefined());
+      }
+    }
+  }
+}
+
+
 #endif  // DEBUG
 
 } }  // namespace v8::internal