diff --git a/lib/jailed.js b/lib/jailed.js
index df5cf51..fa34595 100644
--- a/lib/jailed.js
+++ b/lib/jailed.js
@@ -45,8 +45,8 @@ if (typeof window == 'undefined') {
     }
 }(this, function (exports) {
     var isNode = ((typeof process !== 'undefined') &&
+                  (!process.browser) &&
                   (process.release.name.search(/node|io.js/) !== -1));
-      
 
     /**
      * A special kind of event:
diff --git a/package.json b/package.json
index c840193..8204f66 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,11 @@
     "type": "git",
     "url": "git://github.com/asvd/jailed.git"
   },
+  "browser":
+    {
+      "fs": false,
+      "child_process": false
+    },
   "main": "lib/jailed.js",
   "dependencies": {},
   "devDependencies": {},