diff --git a/.eslintignore b/.eslintignore
index 85bc5d593..d149d0f58 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -7,7 +7,7 @@ external/webL10n/
 external/cmapscompress/
 external/builder/fixtures/
 external/builder/fixtures_esprima/
-external/quickjs/quickjs-eval.js
+external/quickjs/
 src/shared/cffStandardStrings.js
 src/shared/fonts_utils.js
 test/tmp/
diff --git a/.eslintrc b/.eslintrc
index 15643b2a5..128967483 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -197,7 +197,7 @@
     "no-useless-computed-key": "error",
     "no-useless-constructor": "error",
     "no-useless-rename": "error",
-    "no-var": "off",
+    "no-var": "error",
     "object-shorthand": ["error", "always", {
       "avoidQuotes": true,
     }],
diff --git a/examples/.eslintrc b/examples/.eslintrc
index 14eeee2f8..433abdbfa 100644
--- a/examples/.eslintrc
+++ b/examples/.eslintrc
@@ -8,9 +8,4 @@
     "pdfjsLib": false,
     "pdfjsViewer": false,
   },
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
 }
diff --git a/extensions/chromium/.eslintrc b/extensions/chromium/.eslintrc
index ae23570f8..9b12e47c4 100644
--- a/extensions/chromium/.eslintrc
+++ b/extensions/chromium/.eslintrc
@@ -17,6 +17,7 @@
 
   "rules": {
     "mozilla/import-globals": "error",
+    "no-var": "off",
     "object-shorthand": "off",
   },
 }
diff --git a/extensions/firefox/.eslintrc b/extensions/firefox/.eslintrc
index ac538caa5..7c4e6e682 100644
--- a/extensions/firefox/.eslintrc
+++ b/extensions/firefox/.eslintrc
@@ -16,6 +16,7 @@
 
   "rules": {
     // Items different from the mozilla/recommended configuration.
+    "no-var": "off",
 
     // Other rules mozilla/recommended hasn't enabled yet.
     "no-shadow": "error",
diff --git a/external/.eslintrc b/external/.eslintrc
index e3523dce5..64c94ad96 100644
--- a/external/.eslintrc
+++ b/external/.eslintrc
@@ -6,4 +6,9 @@
   "env": {
     "node": true,
   },
+
+  "rules": {
+    // ECMAScript 6
+    "no-var": "off",
+  },
 }
diff --git a/gulpfile.js b/gulpfile.js
index 905420c33..eb515bb63 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -13,7 +13,6 @@
  * limitations under the License.
  */
 /* eslint-env node */
-/* eslint no-var: error */
 /* globals target */
 
 "use strict";
diff --git a/src/.eslintrc b/src/.eslintrc
deleted file mode 100644
index 4a0b538f6..000000000
--- a/src/.eslintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}
diff --git a/src/core/.eslintrc b/src/core/.eslintrc
index cec998b9c..c1831d388 100644
--- a/src/core/.eslintrc
+++ b/src/core/.eslintrc
@@ -4,7 +4,7 @@
   },
 
   "extends": [
-    "../.eslintrc"
+    "../../.eslintrc"
   ],
 
   "env": {
diff --git a/src/shared/.eslintrc b/src/shared/.eslintrc
index cec998b9c..c1831d388 100644
--- a/src/shared/.eslintrc
+++ b/src/shared/.eslintrc
@@ -4,7 +4,7 @@
   },
 
   "extends": [
-    "../.eslintrc"
+    "../../.eslintrc"
   ],
 
   "env": {
diff --git a/systemjs.config.js b/systemjs.config.js
index c5d8185aa..a4a02bc0f 100644
--- a/systemjs.config.js
+++ b/systemjs.config.js
@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/test/add_test.js b/test/add_test.js
index 1f3cd55e9..ca4b4b18b 100644
--- a/test/add_test.js
+++ b/test/add_test.js
@@ -1,3 +1,5 @@
+/* eslint-disable no-var */
+
 const fs = require("fs");
 const crypto = require("crypto");
 const execSync = require("child_process").execSync;
diff --git a/test/chromium/test-telemetry.js b/test/chromium/test-telemetry.js
index c0121c5cb..f03675a50 100755
--- a/test/chromium/test-telemetry.js
+++ b/test/chromium/test-telemetry.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/test/downloadutils.js b/test/downloadutils.js
index 15c0c3c3b..159d15a21 100644
--- a/test/downloadutils.js
+++ b/test/downloadutils.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/test/driver.js b/test/driver.js
index d40062547..717b6caaa 100644
--- a/test/driver.js
+++ b/test/driver.js
@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 /* globals pdfjsLib, pdfjsViewer */
 
 "use strict";
diff --git a/test/font/.eslintrc b/test/font/.eslintrc
deleted file mode 100644
index 4a0b538f6..000000000
--- a/test/font/.eslintrc
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}
diff --git a/test/stats/statcmp.js b/test/stats/statcmp.js
index b0b35c93a..4dd2a44a4 100644
--- a/test/stats/statcmp.js
+++ b/test/stats/statcmp.js
@@ -1,3 +1,5 @@
+/* eslint-disable no-var */
+
 "use strict";
 
 var fs = require("fs");
diff --git a/test/test.js b/test/test.js
index 13ab5461c..957ceb69d 100644
--- a/test/test.js
+++ b/test/test.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/test/testutils.js b/test/testutils.js
index 8113d949f..f4e7eb03d 100644
--- a/test/testutils.js
+++ b/test/testutils.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/test/unit/.eslintrc b/test/unit/.eslintrc
index c78c8b2d8..69af6d92d 100644
--- a/test/unit/.eslintrc
+++ b/test/unit/.eslintrc
@@ -6,8 +6,5 @@
   "rules": {
     // Plugins
     "import/no-unresolved": ["error", { "ignore": ["pdfjs/"] }],
-
-    // ECMAScript 6
-    "no-var": "error",
   },
 }
diff --git a/test/webserver.js b/test/webserver.js
index 68b413858..c2d5b96de 100644
--- a/test/webserver.js
+++ b/test/webserver.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 "use strict";
 
diff --git a/web/.eslintrc b/web/.eslintrc
index 4bf1e6286..08e6f9e38 100644
--- a/web/.eslintrc
+++ b/web/.eslintrc
@@ -6,8 +6,5 @@
   "rules": {
     // Plugins
     "import/no-unresolved": ["error", { "ignore": ["pdfjs-lib"]}],
-
-    // ECMAScript 6
-    "no-var": "error",
   },
 }