diff --git a/src/detectIncognito.ts b/src/detectIncognito.ts
index 5a3ff1c..2d1702a 100644
--- a/src/detectIncognito.ts
+++ b/src/detectIncognito.ts
@@ -69,7 +69,7 @@ export async function detectIncognito(): Promise<{ isPrivate: boolean; browserNa
     function feid (): number {
       let toFixedEngineID = 0
       try {
-        (-1).toFixed(-1)
+        eval(`(-1).toFixed(-1);`);
       } catch (e) {
         toFixedEngineID = (e as Error).message.length // Safari 44, Chrome 51, Firefox 25
       }
@@ -260,4 +260,4 @@ if (typeof window !== 'undefined') {
   window.detectIncognito = detectIncognito;
 }
 
-export default detectIncognito;
\ No newline at end of file
+export default detectIncognito;