diff --git a/fs.js b/fs.js
index 234ab39..85ec1df 100644
--- a/fs.js
+++ b/fs.js
@@ -438,6 +438,21 @@ fs.writeFile = function(filename, data, encodingOrOptions, callback) {};
  */
 fs.writeFileSync = function(filename, data, encodingOrOptions) {};
 
+/**
+ * @param {string} src
+ * @param {string} dest
+ * @param {number|function(...)=} flags
+ * @param {function(...)=} callback
+ */
+fs.copyFile = function(src, dest, flags, callback) {};
+
+/**
+ * @param {string} src
+ * @param {string} dest
+ * @param {number=} flags
+ */
+fs.copyFileSync = function(src, dest, flags) {};
+
 /**
  * @param {string} filename
  * @param {*} data