diff --git a/lib/preprocessor.js b/lib/preprocessor.js
index 05a116f9d..e64826d7b 100644
--- a/lib/preprocessor.js
+++ b/lib/preprocessor.js
@@ -1,4 +1,4 @@
-var fs = require('fs');
+var fs = require('graceful-fs');
 var crypto = require('crypto');
 var mm = require('minimatch');
 
diff --git a/package.json b/package.json
index e1498aab5..f7381a6f4 100644
--- a/package.json
+++ b/package.json
@@ -82,7 +82,8 @@
     "pause": "0.0.1",
     "mime": "~1.2",
     "log4js": "~0.6.3",
-    "useragent": "~2.0.4"
+    "useragent": "~2.0.4",
+    "graceful-fs": "~1.2.1"
   },
   "peerDependencies": {
     "karma-jasmine": "*",
diff --git a/test/unit/preprocessor.spec.coffee b/test/unit/preprocessor.spec.coffee
index f4ac8dc4c..936296587 100644
--- a/test/unit/preprocessor.spec.coffee
+++ b/test/unit/preprocessor.spec.coffee
@@ -13,7 +13,7 @@ describe 'preprocessor', ->
         'a.js': mocks.fs.file 0, 'content'
 
     mocks_ =
-      fs: mockFs
+      'graceful-fs': mockFs
       minimatch: require 'minimatch'
 
     m = mocks.loadFile __dirname + '/../../lib/preprocessor.js', mocks_