--- a/js/xpconnect/src/XPCShellImpl.cpp
+++ b/js/xpconnect/src/XPCShellImpl.cpp
@@ -104,18 +104,23 @@ static bool gIgnoreReportedErrors = fals
 static bool gQuitting = false;
 static bool reportWarnings = true;
 static bool compileOnly = false;
 
 static JSPrincipals *gJSPrincipals = nullptr;
 static nsAutoString *gWorkingDirectory = nullptr;
 
 static bool
-GetLocationProperty(JSContext *cx, HandleObject obj, HandleId id, MutableHandleValue vp)
+GetLocationProperty(JSContext *cx, unsigned argc, Value *vp)
 {
+    CallArgs args = CallArgsFromVp(argc, vp);
+    if (!args.thisv().isObject()) {
+        JS_ReportError(cx, "Unexpected this value for GetLocationProperty");
+        return false;
+    }
 #if !defined(XP_WIN) && !defined(XP_UNIX)
     //XXX: your platform should really implement this
     return false;
 #else
     JS::AutoFilename filename;
     if (JS::DescribeScriptedCaller(cx, &filename) && filename.get()) {
         nsresult rv;
         nsCOMPtr<nsIXPConnect> xpc =
@@ -166,23 +171,23 @@ GetLocationProperty(JSContext *cx, Handl
         if (location) {
             nsCOMPtr<nsIXPConnectJSObjectHolder> locationHolder;
 
             bool symlink;
             // don't normalize symlinks, because that's kind of confusing
             if (NS_SUCCEEDED(location->IsSymlink(&symlink)) &&
                 !symlink)
                 location->Normalize();
-            rv = xpc->WrapNative(cx, obj, location,
+            rv = xpc->WrapNative(cx, &args.thisv().toObject(), location,
                                  NS_GET_IID(nsIFile),
                                  getter_AddRefs(locationHolder));
 
             if (NS_SUCCEEDED(rv) &&
                 locationHolder->GetJSObject()) {
-                vp.set(OBJECT_TO_JSVAL(locationHolder->GetJSObject()));
+                args.rval().setObject(*locationHolder->GetJSObject());
             }
         }
     }
 
     return true;
 #endif
 }
 
@@ -1492,18 +1497,20 @@ XRE_XPCShellMain(int argc, char **argv, 
             }
 
             JS_SetPrivate(envobj, envp);
 
             nsAutoString workingDirectory;
             if (GetCurrentWorkingDirectory(workingDirectory))
                 gWorkingDirectory = &workingDirectory;
 
-            JS_DefineProperty(cx, glob, "__LOCATION__", JS::UndefinedHandleValue, 0,
-                              GetLocationProperty, nullptr);
+            JS_DefineProperty(cx, glob, "__LOCATION__", JS::UndefinedHandleValue,
+                              JSPROP_NATIVE_ACCESSORS | JSPROP_SHARED,
+                              JS_CAST_NATIVE_TO(GetLocationProperty, JSPropertyOp),
+                              nullptr);
 
             // We are almost certainly going to run script here, so we need an
             // AutoEntryScript. This is Gecko-specific and not in any spec.
             dom::AutoEntryScript aes(backstagePass);
             result = ProcessArgs(aes.cx(), glob, argv, argc, &dirprovider);
 
             JS_DropPrincipals(rt, gJSPrincipals);
             JS_SetAllNonReservedSlotsToUndefined(aes.cx(), glob);