diff --git a/.eslintrc.json b/.eslintrc.json
index fa180c2..f4ce5ab 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -3,5 +3,8 @@
   "env": {
     "jest/globals": true
   },
+  "globals": {
+    "fetch": false
+  },  
   "plugins": ["jest"]
 }
\ No newline at end of file
diff --git a/lib/OAuth2Fetch.js b/lib/OAuth2Fetch.js
index 0666573..cf49fbd 100644
--- a/lib/OAuth2Fetch.js
+++ b/lib/OAuth2Fetch.js
@@ -1,3 +1,5 @@
+'use strict';
+
 module.exports = Number(process.versions.node.split('.')[0]) >= 18
   ? fetch // Use native fetch on Node 18 and above
   : require('node-fetch');