diff --git a/src/runtime/runtime-debug.cc b/src/runtime/runtime-debug.cc
index 51e7b70e44..1e6a442b50 100644
--- a/src/runtime/runtime-debug.cc
+++ b/src/runtime/runtime-debug.cc
@@ -294,14 +294,20 @@ class FrameInspector {
   FrameInspector(JavaScriptFrame* frame, int inlined_jsframe_index,
                  Isolate* isolate)
       : frame_(frame), deoptimized_frame_(NULL), isolate_(isolate) {
-    // Calculate the deoptimized frame.
-    if (frame->is_optimized()) {
-      deoptimized_frame_ = Deoptimizer::DebuggerInspectableFrame(
-          frame, inlined_jsframe_index, isolate);
-    }
     has_adapted_arguments_ = frame_->has_adapted_arguments();
     is_bottommost_ = inlined_jsframe_index == 0;
     is_optimized_ = frame_->is_optimized();
+    // Calculate the deoptimized frame.
+    if (frame->is_optimized()) {
+      // TODO(turbofan): Revisit once we support deoptimization.
+      if (frame->LookupCode()->is_turbofanned() && !FLAG_turbo_deoptimization) {
+        is_optimized_ = false;
+        return;
+      }
+
+      deoptimized_frame_ = Deoptimizer::DebuggerInspectableFrame(
+          frame, inlined_jsframe_index, isolate);
+    }
   }
 
   ~FrameInspector() {
@@ -325,6 +331,10 @@ class FrameInspector {
                          : frame_->GetParameter(index);
   }
   Object* GetExpression(int index) {
+    // TODO(turbofan): Revisit once we support deoptimization.
+    if (frame_->LookupCode()->is_turbofanned() && !FLAG_turbo_deoptimization) {
+      return isolate_->heap()->undefined_value();
+    }
     return is_optimized_ ? deoptimized_frame_->GetExpression(index)
                          : frame_->GetExpression(index);
   }
diff --git a/test/mjsunit/regress/regress-crbug-465298.js b/test/mjsunit/regress/regress-crbug-465298.js
new file mode 100644
index 0000000000..0b2827b0d2
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-465298.js
@@ -0,0 +1,55 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --noturbo-osr --expose-debug-as debug
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = { thrower: thrower, debugme: debugme }
+
+// Get the Debug object exposed from the debug context global object.
+Debug = debug.Debug;
+
+var listenerCalled = false;
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Break) {
+      var frame = exec_state.frame(1);
+      assertEquals(m.foo, frame.func().value());
+      listenerCalled = true;
+    }
+  } catch (e) {
+    print("Caught: " + e + " " + e.stack);
+  };
+}
+
+function thrower() { throw "boom"; }
+function debugme() { Debug.setListener(listener); debugger; }
+
+function Module(stdlib, foreign, heap) {
+  "use asm";
+  var thrower = foreign.thrower;
+  var debugme = foreign.debugme;
+  function foo(i) {
+    i = i|0;
+    var a = 101;  // Local variables exist ...
+    var b = 102;  // ... to make the debugger ...
+    var c = 103;  // ... inspect them during break.
+    if (i > 0) {
+      debugme();
+      i = 23;
+    } else {
+      thrower();
+      i = 42;
+    }
+    return i|0;
+  }
+  return { foo: foo };
+}
+
+var m = Module(stdlib, foreign, buffer);
+
+assertThrows("m.foo(0)");
+assertEquals(23, m.foo(1));
+assertTrue(listenerCalled);