diff --git a/assets/js/themes.js b/assets/js/themes.js
index 9388d422..223d01f5 100644
--- a/assets/js/themes.js
+++ b/assets/js/themes.js
@@ -17,7 +17,7 @@ toggle_theme.addEventListener('click', function () {
 });
 
 window.addEventListener('storage', function (e) {
-    if (e.key == 'dark_mode') {
+    if (e.key === 'dark_mode') {
         update_mode(e.newValue);
     }
 });
@@ -38,11 +38,11 @@ function set_mode (bool) {
 }
 
 function update_mode (mode) {
-    if (mode == 'true' /* for backwards compatibility */ || mode == 'dark') {
+    if (mode === 'true' /* for backwards compatibility */ || mode === 'dark') {
         // If dark mode preference set
         set_mode(true);
     }
-    else if (mode != 'light' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
+    else if (mode !== 'light' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
         // If no preference set, but the browser tells us that the operating system has a dark theme
         set_mode(true);
     }