diff --git a/src/crankshaft/hydrogen-instructions.h b/src/crankshaft/hydrogen-instructions.h
index 514882145f2..b10e3ab819c 100644
--- a/src/crankshaft/hydrogen-instructions.h
+++ b/src/crankshaft/hydrogen-instructions.h
@@ -4370,6 +4370,11 @@ class HAdd final : public HArithmeticBinaryOperation {
       SetChangesFlag(kNewSpacePromotion);
       ClearFlag(kAllowUndefinedAsNaN);
     }
+    if (!right()->type().IsTaggedNumber() &&
+        !right()->representation().IsDouble() &&
+        !right()->representation().IsSmiOrInteger32()) {
+      ClearFlag(kAllowUndefinedAsNaN);
+    }
   }
 
   Representation RepresentationFromInputs() override;
diff --git a/test/mjsunit/compiler/regress-5074.js b/test/mjsunit/compiler/regress-5074.js
new file mode 100644
index 00000000000..903b54ad980
--- /dev/null
+++ b/test/mjsunit/compiler/regress-5074.js
@@ -0,0 +1,18 @@
+// 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
+
+var s = [,0.1];
+
+function foo(a, b) {
+  var x = s[a];
+  s[1] = 0.1;
+  return x + b;
+}
+
+assertEquals(2.1, foo(1, 2));
+assertEquals(2.1, foo(1, 2));
+%OptimizeFunctionOnNextCall(foo);
+assertEquals("undefined2", foo(0, "2"));