diff --git a/src/components/observers/themeWatcher.tsx b/src/components/observers/themeWatcher.tsx
index 57dcd7e..f6c997d 100644
--- a/src/components/observers/themeWatcher.tsx
+++ b/src/components/observers/themeWatcher.tsx
@@ -3,8 +3,8 @@ import { useSetAtom } from "jotai";
 import { themeAtom } from "../../store/themeAtom";
 
 const getButtonBackgroundColor = () => {
-  let elem = parent.document.querySelector("button.ui__button");
-  let style = parent.window.getComputedStyle(elem);
+  const elem = parent.document.querySelector("button.ui__button");
+  const style = parent.window.getComputedStyle(elem);
 
   return style.backgroundColor;
 };
diff --git a/src/parsers/chess/chessConfig.ts b/src/parsers/chess/chessConfig.ts
index 407c8ac..55e0a5d 100644
--- a/src/parsers/chess/chessConfig.ts
+++ b/src/parsers/chess/chessConfig.ts
@@ -91,7 +91,7 @@ class ChessConfig {
   };
 
   private parseSquares = (line: string, limit: number = null): Square[] => {
-    let items = line.split(" ").map((item) => item.trim() as Square);
+    const items = line.split(" ").map((item) => item.trim() as Square);
 
     if (limit) {
       return items.slice(0 - limit);