diff --git a/lib/service-worker.js b/lib/service-worker.js
index d327501..f6973a6 100644
--- a/lib/service-worker.js
+++ b/lib/service-worker.js
@@ -4,7 +4,7 @@ var brocWriter = require("broccoli-writer");
 var helpers = require("broccoli-kitchen-sink-helpers");
 var funnel = require('broccoli-funnel');
 var swToolboxFile = require.resolve('sw-toolbox/sw-toolbox.js');
-var swToolboxMapFile = require.resolve('sw-toolbox/sw-toolbox.map.json');
+var swToolboxMapFile = require.resolve('sw-toolbox/sw-toolbox.js.map');
 var toolboxLocation = 'sw-toolbox.js';
 var rsvp= require('rsvp');
 var BroccoliServiceWorker = function BroccoliServiceWorker(inTree, options) {
diff --git a/package.json b/package.json
index e2f4fe6..3e4e2ab 100644
--- a/package.json
+++ b/package.json
@@ -32,6 +32,6 @@
     "broccoli-writer": "~0.1.1",
     "rsvp": "^3.1.0",
     "stringifile": "^0.1.1",
-    "sw-toolbox": "^3.1.1"
+    "sw-toolbox": "^3.4.0"
   }
 }