diff --git a/qobuz_dl/qopy.py b/qobuz_dl/qopy.py
index 87b3265..e7dabab 100644
--- a/qobuz_dl/qopy.py
+++ b/qobuz_dl/qopy.py
@@ -199,3 +199,5 @@ class Client:
             if self.test_secret(secret):
                 self.sec = secret
                 break
+        if not hasattr(self, "sec"):
+            raise InvalidAppSecretError("Invalid app secret.\n" + RESET)