diff --git a/lib/ignored-paths.js b/lib/ignored-paths.js
index 0d9152495eca..e5ba8450ff9e 100644
--- a/lib/ignored-paths.js
+++ b/lib/ignored-paths.js
@@ -37,7 +37,6 @@ const DEFAULT_OPTIONS = {
     cwd: process.cwd()
 };
 
-
 //------------------------------------------------------------------------------
 // Helpers
 //------------------------------------------------------------------------------
@@ -80,6 +79,7 @@ class IgnoredPaths {
      */
     constructor(options) {
         options = mergeDefaultOptions(options);
+        this.cache = {};
 
         /**
          * add pattern to node-ignore instance
@@ -91,17 +91,29 @@ class IgnoredPaths {
             return ig.addPattern(pattern);
         }
 
+        /**
+         * read ignore filepath
+         * @param {string} filepath, file to add to ig
+         * @returns {array} raw ignore rules
+         */
+        function readIgnoreFile(filepath) {
+            return fs.readFileSync(filepath, "utf8");
+        }
+
         /**
          * add ignore file to node-ignore instance
          * @param {Object} ig, instance of node-ignore
          * @param {string} filepath, file to add to ig
+         * @param {string} cache, file object to add to ig
          * @returns {array} raw ignore rules
          */
-        function addIgnoreFile(ig, filepath) {
+        function addIgnoreFile(ig, filepath, cache) {
             ig.ignoreFiles.push(filepath);
-            return ig.add(fs.readFileSync(filepath, "utf8"));
+            return ig.add(cache[filepath]);
         }
 
+
+
         this.defaultPatterns = [].concat(DEFAULT_IGNORE_DIRS, options.patterns || []);
         this.baseDir = options.cwd;
 
@@ -155,8 +167,11 @@ class IgnoredPaths {
             if (ignorePath) {
                 debug(`Adding ${ignorePath}`);
                 this.baseDir = path.dirname(path.resolve(options.cwd, ignorePath));
-                addIgnoreFile(this.ig.custom, ignorePath);
-                addIgnoreFile(this.ig.default, ignorePath);
+                if (!this.cache[ignorePath]) {
+                    this.cache[ignorePath] = readIgnoreFile(ignorePath);
+                }
+                addIgnoreFile(this.ig.custom, ignorePath, this.cache);
+                addIgnoreFile(this.ig.default, ignorePath, this.cache);
             }
 
             if (options.ignorePattern) {