diff --git a/src/compiler/ast-loop-assignment-analyzer.cc b/src/compiler/ast-loop-assignment-analyzer.cc
index 334c5978a86..97da140b81c 100644
--- a/src/compiler/ast-loop-assignment-analyzer.cc
+++ b/src/compiler/ast-loop-assignment-analyzer.cc
@@ -254,10 +254,12 @@ void ALAA::VisitForStatement(ForStatement* loop) {
 
 
 void ALAA::VisitForInStatement(ForInStatement* loop) {
+  Expression* l = loop->each();
   Enter(loop);
-  Visit(loop->each());
+  Visit(l);
   Visit(loop->subject());
   Visit(loop->body());
+  if (l->IsVariableProxy()) AnalyzeAssignment(l->AsVariableProxy()->var());
   Exit(loop);
 }
 
diff --git a/test/mjsunit/regress/regress-crbug-647887.js b/test/mjsunit/regress/regress-crbug-647887.js
new file mode 100644
index 00000000000..84e598d5aa9
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-647887.js
@@ -0,0 +1,14 @@
+// Copyright 2016 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: --allow-natives-syntax
+
+function f(obj) {
+  var key;
+  for (key in obj) { }
+  return key === undefined;
+}
+
+%OptimizeFunctionOnNextCall(f);
+assertFalse(f({ foo:0 }));