diff --git a/lib/ember-addon.js b/lib/ember-addon.js
index 31d2bf9..7435f68 100644
--- a/lib/ember-addon.js
+++ b/lib/ember-addon.js
@@ -15,7 +15,8 @@ ServiceWorkerIncludes.prototype.toTree = function(tree, inputPath, outputPath, i
   if (inputPath === '/') {
     this.swIncludeTree = tree;
     this.swIncludeTree = funnel(tree, {
-      srcDir:  serviceWorkersDir
+      srcDir:  serviceWorkersDir,
+      allowEmpty: true
     });
   }
   return funnel(tree, {
diff --git a/lib/service-worker.js b/lib/service-worker.js
index e740db2..f2282bb 100644
--- a/lib/service-worker.js
+++ b/lib/service-worker.js
@@ -105,7 +105,7 @@ BroccoliServiceWorker.prototype.write = function(readTree, destDir) {
       }
       if (swIncludeFiles && swIncludeFiles.length) {
         lines = lines.concat(swIncludeFiles.map(function(file) {
-          return fs.readFileSync(file)
+          return fs.readFileSync(file);
         }).join(';\n'));
       }
       if (swIncludeDir) {
@@ -134,7 +134,7 @@ BroccoliServiceWorker.prototype.write = function(readTree, destDir) {
       fs.writeFileSync(path.join(destDir, serviceWorkerFile), lines.join("\n"));
       fs.writeFileSync(path.join(destDir, toolboxLocation), fs.readFileSync(swToolboxFile));
       if (debug) {
-        fs.writeFileSync(path.join(destDir, 'sw-toolbox.map.json'), fs.readFileSync(swToolboxMapFile));
+        fs.writeFileSync(path.join(destDir, 'sw-toolbox.js.map'), fs.readFileSync(swToolboxMapFile));
       }
     });
   });