diff --git a/js/src/methodjit/Compiler.cpp b/js/src/methodjit/Compiler.cpp
index 9259e9d18be..ed20076c0db 100644
--- a/js/src/methodjit/Compiler.cpp
+++ b/js/src/methodjit/Compiler.cpp
@@ -596,6 +596,13 @@ mjit::Compiler::generateMethod()
             jsop_getprop_slow();
           END_CASE(JSOP_GETPROP)
 
+          BEGIN_CASE(JSOP_LENGTH)
+            prepareStubCall();
+            stubCall(stubs::Length, Uses(1), Defs(1));
+            frame.pop();
+            frame.pushSynced();
+          END_CASE(JSOP_LENGTH)
+
           BEGIN_CASE(JSOP_GETELEM)
             prepareStubCall();
             stubCall(stubs::GetElem, Uses(2), Defs(1));
diff --git a/js/src/methodjit/StubCalls.cpp b/js/src/methodjit/StubCalls.cpp
index c3448dfa2c6..a6613748e05 100644
--- a/js/src/methodjit/StubCalls.cpp
+++ b/js/src/methodjit/StubCalls.cpp
@@ -2163,6 +2163,33 @@ stubs::CallProp(VMFrame &f, JSAtom *atom)
 #endif /* JS_HAS_NO_SUCH_METHOD */
 }
 
+void JS_FASTCALL
+stubs::Length(VMFrame &f)
+{
+    JSFrameRegs &regs = f.regs;
+    Value *vp = &regs.sp[-1];
+
+    if (vp->isString()) {
+        vp->setInt32(vp->asString()->length());
+        return;
+    } else if (vp->isObject()) {
+        JSObject *obj = &vp->asObject();
+        if (obj->isArray()) {
+            jsuint length = obj->getArrayLength();
+            regs.sp[-1].setDouble(length);
+            return;
+        } else if (obj->isArguments() && !obj->isArgsLengthOverridden()) {
+            uint32 length = obj->getArgsLength();
+            JS_ASSERT(length < INT32_MAX);
+            regs.sp[-1].setInt32(int32_t(length));
+            return;
+        }
+    }
+
+    if (!InlineGetProp(f))
+        THROW();
+}
+
 void JS_FASTCALL
 stubs::Iter(VMFrame &f, uint32 flags)
 {
diff --git a/js/src/methodjit/StubCalls.h b/js/src/methodjit/StubCalls.h
index 6367803cf35..6d78e0a4cdb 100644
--- a/js/src/methodjit/StubCalls.h
+++ b/js/src/methodjit/StubCalls.h
@@ -67,6 +67,7 @@ void JS_FASTCALL Name(VMFrame &f, uint32 index);
 void JS_FASTCALL GetProp(VMFrame &f);
 void JS_FASTCALL GetElem(VMFrame &f);
 void JS_FASTCALL SetElem(VMFrame &f);
+void JS_FASTCALL Length(VMFrame &f);
 void JS_FASTCALL CallName(VMFrame &f, uint32 index);
 void JS_FASTCALL GetUpvar(VMFrame &f, uint32 index);