diff --git a/packages/utils/src/base64url.ts b/packages/utils/src/base64url.ts
index f4e8b3e..62753c0 100644
--- a/packages/utils/src/base64url.ts
+++ b/packages/utils/src/base64url.ts
@@ -47,6 +47,6 @@ export class Base64url {
     }
 }
 
-export function base64ToBase64URL(base64: string) {
+function base64ToBase64URL(base64: string) {
     return base64.replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '')
 }