diff --git a/tools/internal-rules/lib/rules/check-i18n-keys.js b/tools/internal-rules/lib/rules/check-i18n-keys.js
index 3fcafaf9..d3c31f8b 100644
--- a/tools/internal-rules/lib/rules/check-i18n-keys.js
+++ b/tools/internal-rules/lib/rules/check-i18n-keys.js
@@ -21,12 +21,10 @@ module.exports = {
         function extractKeys(node, parentKey = "") {
             const keys = [];
             let properties = node.properties;
-            let fileContent;
-            let ast;
 
             if (typeof node === "string") {
-                fileContent = fs.readFileSync(node, "utf8");
-                ast = parse(fileContent, {
+                const fileContent = fs.readFileSync(node, "utf8");
+                const ast = parse(fileContent, {
                     sourceType: "module",
                     plugins: ["typescript", "jsx"]
                 });