diff --git a/src/debug.cc b/src/debug.cc
index 1afbfc1068..5d386cc04b 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -1787,9 +1787,7 @@ void Debug::FramesHaveBeenDropped(StackFrame::Id new_break_frame_id,
   thread_local_.frame_drop_mode_ = mode;
   thread_local_.break_frame_id_ = new_break_frame_id;
   thread_local_.restarter_frame_function_pointer_ =
-  // Temporary disabled for failing test investigation.
-  //    restarter_frame_function_pointer;
-      NULL;
+      restarter_frame_function_pointer;
 }
 
 
diff --git a/src/serialize.cc b/src/serialize.cc
index 0e283f4618..3988b4a893 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -237,6 +237,10 @@ void ExternalReferenceTable::PopulateTable() {
       DEBUG_ADDRESS,
       Debug::k_debug_break_return_address << kDebugIdShift,
       "Debug::debug_break_return_address()");
+  Add(Debug_Address(Debug::k_restarter_frame_function_pointer).address(),
+      DEBUG_ADDRESS,
+      Debug::k_restarter_frame_function_pointer << kDebugIdShift,
+      "Debug::restarter_frame_function_pointer_address()");
   const char* debug_register_format = "Debug::register_address(%i)";
   int dr_format_length = StrLength(debug_register_format);
   for (int i = 0; i < kNumJSCallerSaved; ++i) {
@@ -478,6 +482,7 @@ ExternalReferenceEncoder::ExternalReferenceEncoder()
 
 uint32_t ExternalReferenceEncoder::Encode(Address key) const {
   int index = IndexOf(key);
+  ASSERT(key == NULL || index >= 0);
   return index >=0 ? ExternalReferenceTable::instance()->code(index) : 0;
 }