diff --git a/frappe/auth.py b/frappe/auth.py
index 27aff63371..648f72f8e7 100644
--- a/frappe/auth.py
+++ b/frappe/auth.py
@@ -665,6 +665,8 @@ def validate_api_key_secret(api_key, api_secret, frappe_authorization_source=Non
 		if frappe.local.login_manager.user in ("", "Guest"):
 			frappe.set_user(user)
 		frappe.local.form_dict = form_dict
+	else:
+		raise frappe.AuthenticationError
 
 
 def validate_auth_via_hooks():