diff --git a/.eslintignore b/.eslintignore
index e72c6d82f7049..7a05f72ce35a6 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -10,7 +10,6 @@ external/quickjs/
 src/shared/cffStandardStrings.js
 src/shared/fonts_utils.js
 test/tmp/
-test/features/
 test/pdfs/
 test/resources/
 *~/
diff --git a/external/.eslintrc b/external/.eslintrc
index 64c94ad96cf36..e3523dce526ed 100644
--- a/external/.eslintrc
+++ b/external/.eslintrc
@@ -6,9 +6,4 @@
   "env": {
     "node": true,
   },
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "off",
-  },
 }
diff --git a/external/builder/.eslintrc b/external/builder/.eslintrc
deleted file mode 100644
index 4a0b538f60890..0000000000000
--- a/external/builder/.eslintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}
diff --git a/external/cmapscompress/.eslintrc b/external/cmapscompress/.eslintrc
deleted file mode 100644
index 4a0b538f60890..0000000000000
--- a/external/cmapscompress/.eslintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}
diff --git a/external/dist/webpack.js b/external/dist/webpack.js
index 7c1ce09ba4d84..45598babcb9f5 100644
--- a/external/dist/webpack.js
+++ b/external/dist/webpack.js
@@ -15,8 +15,8 @@
 
 "use strict";
 
-var pdfjs = require("./build/pdf.js");
-var PdfjsWorker = require("worker-loader?esModule=false&filename=[name].js!./build/pdf.worker.js");
+const pdfjs = require("./build/pdf.js");
+const PdfjsWorker = require("worker-loader?esModule=false&filename=[name].js!./build/pdf.worker.js");
 
 if (typeof window !== "undefined" && "Worker" in window) {
   pdfjs.GlobalWorkerOptions.workerPort = new PdfjsWorker();
diff --git a/external/importL10n/.eslintrc b/external/importL10n/.eslintrc
deleted file mode 100644
index 4a0b538f60890..0000000000000
--- a/external/importL10n/.eslintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}
diff --git a/external/systemjs/plugin-babel-cached.js b/external/systemjs/plugin-babel-cached.js
index d0f2e711ce371..518dfa4ce696f 100644
--- a/external/systemjs/plugin-babel-cached.js
+++ b/external/systemjs/plugin-babel-cached.js
@@ -12,6 +12,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
+
 var babel = require("plugin-babel");
 
 var cacheExpiration = 60 /* min */ * 60 * 1000;
diff --git a/external/webpack/pdfjsdev-loader.js b/external/webpack/pdfjsdev-loader.js
index 1bbcacf71237e..c290b639c4eb4 100644
--- a/external/webpack/pdfjsdev-loader.js
+++ b/external/webpack/pdfjsdev-loader.js
@@ -12,12 +12,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint-env node */
 
 "use strict";
 
-var preprocessor2 = require("../builder/preprocessor2.js");
-var path = require("path");
+const preprocessor2 = require("../builder/preprocessor2.js");
+const path = require("path");
 
 module.exports = function (source) {
   // Options must be specified, ignoring request if not.
@@ -26,17 +25,17 @@ module.exports = function (source) {
   }
   this.cacheable();
 
-  var filePath = this.resourcePath;
-  var context = this.rootContext;
-  var sourcePath = path.relative(context, filePath).split(path.sep).join("/");
+  const filePath = this.resourcePath;
+  const context = this.rootContext;
+  const sourcePath = path.relative(context, filePath).split(path.sep).join("/");
 
-  var ctx = Object.create(this.query);
+  const ctx = Object.create(this.query);
   ctx.sourceMap = true;
   ctx.sourceFile = sourcePath;
 
-  var callback = this.callback;
-  var sourceAndMap = preprocessor2.preprocessPDFJSCode(ctx, source);
-  var map = sourceAndMap.map.toJSON();
+  const callback = this.callback;
+  const sourceAndMap = preprocessor2.preprocessPDFJSCode(ctx, source);
+  const map = sourceAndMap.map.toJSON();
   // escodegen does not embed source -- setting map's sourcesContent.
   map.sourcesContent = [source];
   callback(null, sourceAndMap.code, map);