diff --git a/src/webui/www/eslint.config.mjs b/src/webui/www/eslint.config.mjs
index 204e3bcb1..ed1d8c7f8 100644
--- a/src/webui/www/eslint.config.mjs
+++ b/src/webui/www/eslint.config.mjs
@@ -30,6 +30,7 @@ export default [
             "no-undef": "off",
             "no-unused-vars": "off",
             "no-var": "error",
+            "operator-assignment": "error",
             "prefer-arrow-callback": "error",
             "prefer-const": "error",
             "Stylistic/no-mixed-operators": [
diff --git a/src/webui/www/private/scripts/misc.js b/src/webui/www/private/scripts/misc.js
index dbd52c71a..d9654a08a 100644
--- a/src/webui/www/private/scripts/misc.js
+++ b/src/webui/www/private/scripts/misc.js
@@ -114,15 +114,15 @@ window.qBittorrent.Misc = (function() {
         if (minutes < 60)
             return "QBT_TR(%1m)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(minutes));
         let hours = minutes / 60;
-        minutes = minutes % 60;
+        minutes %= 60;
         if (hours < 24)
             return "QBT_TR(%1h %2m)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(hours)).replace("%2", parseInt(minutes));
         let days = hours / 24;
-        hours = hours % 24;
+        hours %= 24;
         if (days < 365)
             return "QBT_TR(%1d %2h)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(days)).replace("%2", parseInt(hours));
         const years = days / 365;
-        days = days % 365;
+        days %= 365;
         return "QBT_TR(%1y %2d)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(years)).replace("%2", parseInt(days));
     };