diff --git a/src/js/codemirror/mode/raw-settings.js b/src/js/codemirror/mode/raw-settings.js
index 34585d9..c09d801 100644
--- a/src/js/codemirror/mode/raw-settings.js
+++ b/src/js/codemirror/mode/raw-settings.js
@@ -23,7 +23,7 @@
 
 'use strict';
 
-CodeMirror.defineMode("raw-settings", function() {
+CodeMirror.defineMode('raw-settings', function() {
     return {
         token: function(stream) {
             if ( stream.sol() ) {
diff --git a/src/js/contentscript-no-inline-script.js b/src/js/contentscript-no-inline-script.js
index 746d744..e172274 100644
--- a/src/js/contentscript-no-inline-script.js
+++ b/src/js/contentscript-no-inline-script.js
@@ -26,7 +26,7 @@
 // https://github.com/hackademix/noscript/commit/6e80d3f130773fc9a9123c5c4c2e97d63e90fa2a
 
 (function() {
-    let html = document.documentElement;
+    const html = document.documentElement;
     if ( html instanceof HTMLElement === false ) { return; }
 
     let meta;
@@ -45,8 +45,8 @@
     //
     // The CSP directive is enforced as soon as the meta tag is inserted:
     // > Enforce the policy policy.
-    let head = document.head,
-        parent = head;
+    const head = document.head;
+    let parent = head;
     if ( parent === null ) {
         parent = document.createElement('head');
         html.appendChild(parent);