diff --git a/package.json b/package.json
index 1343b30b9c..1e95a6620e 100644
--- a/package.json
+++ b/package.json
@@ -67,8 +67,7 @@
     "proj4": "2.3.14",
     "resemblejs": "2.2.0",
     "sinon": "1.17.3",
-    "slimerjs": "0.906.1",
-    "wrench": "1.5.8"
+    "slimerjs": "0.906.1"
   },
   "eslintConfig": {
     "extends": "openlayers",
diff --git a/tasks/test-coverage.js b/tasks/test-coverage.js
index a11eef1285..61a8141059 100644
--- a/tasks/test-coverage.js
+++ b/tasks/test-coverage.js
@@ -8,8 +8,8 @@
  */
 
 var fs = require('fs');
+var fse = require('fs-extra');
 var istanbul = require('istanbul');
-var wrench = require('wrench');
 var path = require('path');
 var glob = require('glob');
 
@@ -28,17 +28,10 @@ var collector = new istanbul.Collector();
 
 // General options used for the resource shuffling / directory copying
 var copyOpts = {
-  // Whether to overwrite existing directory or not
-  forceDelete: true,
-  // Whether to copy hidden Unix files or not (preceding .)
-  excludeHiddenUnix: false,
-  // If we're overwriting something and the file already exists, keep the
-  // existing
-  preserveFiles: false,
+  // Overwrite existing file or directory
+  clobber: true,
   // Preserve the mtime and atime when copying files
-  preserveTimestamps: true,
-  // Whether to follow symlinks or not when copying files
-  inflateSymlinks: false
+  preserveTimestamps: true
 };
 
 /**
@@ -49,28 +42,6 @@ var log = function(msg) {
   process.stdout.write(msg + '\n');
 };
 
-
-/**
- * A utility method to recursively delete a non-empty folder.
- *
- * See http://www.geedew.com/remove-a-directory-that-is-not-empty-in-nodejs/
- * adjusted to use path.join
- * @param {string} p Path to the directory.
- */
-var deleteFolderRecursive = function(p) {
-  if (fs.existsSync(p)) {
-    fs.readdirSync(p).forEach(function(file,index) {
-      var curPath = path.join(p, file);
-      if (fs.lstatSync(curPath).isDirectory()) { // recurse
-        deleteFolderRecursive(curPath);
-      } else { // delete file
-        fs.unlinkSync(curPath);
-      }
-    });
-    fs.rmdirSync(p);
-  }
-};
-
 /**
  * Creates folders for backup and instrumentation and copies the contents of the
  * current src folder into them.
@@ -87,9 +58,9 @@ var setupBackupAndInstrumentationDir = function() {
   }
 
   log('• copy src files to backup folder');
-  wrench.copyDirSyncRecursive(dir, backupDir, copyOpts);
+  fse.copySync(dir, backupDir, copyOpts);
   log('• copy src files to instrumentation folder');
-  wrench.copyDirSyncRecursive(dir, instrumentedDir, copyOpts);
+  fse.copySync(dir, instrumentedDir, copyOpts);
 };
 
 /**
@@ -99,11 +70,11 @@ var setupBackupAndInstrumentationDir = function() {
  */
 var revertBackupAndInstrumentationDir = function() {
   log('• copy original src back to src folder');
-  wrench.copyDirSyncRecursive(backupDir, dir, copyOpts);
+  fse.copySync(backupDir, dir, copyOpts);
   log('• delete backup directory');
-  deleteFolderRecursive(backupDir);
+  fse.removeSync(backupDir);
   log('• delete instrumentation directory');
-  deleteFolderRecursive(instrumentedDir);
+  fse.removeSync(instrumentedDir);
 };
 
 
@@ -161,7 +132,7 @@ var foundAllJavaScriptSourceFiles = function(err, files) {
   log('  • done. ' + cnt + ' files instrumented');
   log('• copy instrumented src back to src folder');
 
-  wrench.copyDirSyncRecursive(instrumentedDir, dir, copyOpts);
+  fse.copySync(instrumentedDir, dir, copyOpts);
 
   log('• run test suite on instrumented code');
   runTestsuite({coverage: true, reporter: 'dot'}, collectAndWriteCoverageData);