diff --git a/Cakefile b/Cakefile
index d92f6b2..e041454 100644
--- a/Cakefile
+++ b/Cakefile
@@ -149,7 +149,7 @@ task 'min', 'Create minimized version of library', ->
 
 task 'gem', 'Build RubyGem package', ->
   fs.removeSync('build/') if path.existsSync('build/')
-  fs.mkdirSync('build/lib/assets/javascripts/')
+  fs.mkdirsSync('build/lib/assets/javascripts/')
 
   copy = require('fs-extra/lib/copy').copyFileSync
   copy('gem/visibilityjs.gemspec', 'build/visibilityjs.gemspec')
diff --git a/package.json b/package.json
index c8fb860..df102e0 100644
--- a/package.json
+++ b/package.json
@@ -2,13 +2,13 @@
   "name": "visibility.js",
   "version": "0.6.0",
   "devDependencies": {
-    "coffee-script": "1.3.3",
-    "mocha":         "1.5.0",
-    "chai":          "1.2.0",
-    "sinon":         "1.4.2",
+    "coffee-script": "1.4.0",
+    "mocha":         "1.6.0",
+    "chai":          "1.3.0",
+    "sinon":         "1.5.0",
     "sinon-chai":    "2.1.2",
-    "fs-extra":      "0.2.1",
-    "glob":          "3.1.12",
-    "uglify-js":     "1.3.3"
+    "fs-extra":      "0.3.2",
+    "glob":          "3.1.14",
+    "uglify-js":     "1.3.4"
   }
 }