diff -u b/core/misc/active-link.es6.js b/core/misc/active-link.es6.js
--- b/core/misc/active-link.es6.js
+++ b/core/misc/active-link.es6.js
@@ -41,16 +41,17 @@
       selectors = [].concat(
         // Links without any hreflang attributes (most of them).
         originalSelectors.map(
-          selector => `${selector}:not([data-drupal-language]):not([hreflang])`,
+          (selector) =>
+            `${selector}:not([data-drupal-language]):not([hreflang])`,
         ),
         // Links li with data-drupal-language equals to the current language.
         originalSelectors.map(
-          selector =>
+          (selector) =>
             `li${selector}[data-drupal-language="${path.currentLanguage}"]`,
         ),
         // Links a with hreflang equals to the current language.
         originalSelectors.map(
-          selector => `a${selector}[hreflang="${path.currentLanguage}"]`,
+          (selector) => `a${selector}[hreflang="${path.currentLanguage}"]`,
         ),
       );
 
diff -u b/core/misc/active-link.js b/core/misc/active-link.js
--- b/core/misc/active-link.js
+++ b/core/misc/active-link.js
@@ -19,11 +19,11 @@
       }
 
       selectors = [].concat(originalSelectors.map(function (selector) {
-        return selector + ':not([data-drupal-language]):not([hreflang])';
+        return "".concat(selector, ":not([data-drupal-language]):not([hreflang])");
       }), originalSelectors.map(function (selector) {
-        return 'li' + selector + '[data-drupal-language="' + path.currentLanguage + '"]';
+        return "li".concat(selector, "[data-drupal-language=\"").concat(path.currentLanguage, "\"]");
       }), originalSelectors.map(function (selector) {
-        return 'a' + selector + '[hreflang="' + path.currentLanguage + '"]';
+        return "a".concat(selector, "[hreflang=\"").concat(path.currentLanguage, "\"]");
       }));
       selectors = selectors.map(function (current) {
         return current + querySelector;