diff --git a/swh/auth/pytest_plugin.py b/swh/auth/pytest_plugin.py
--- a/swh/auth/pytest_plugin.py
+++ b/swh/auth/pytest_plugin.py
@@ -147,6 +147,7 @@
             self.refresh_token.side_effect = exception
             self.userinfo.side_effect = exception
             self.logout.side_effect = exception
+            self.login.side_effect = exception
 
 
 def keycloak_mock_factory(
diff --git a/swh/auth/tests/test_keycloak.py b/swh/auth/tests/test_keycloak.py
--- a/swh/auth/tests/test_keycloak.py
+++ b/swh/auth/tests/test_keycloak.py
@@ -53,6 +53,9 @@
     with pytest.raises(KeycloakError):
         keycloak_mock.authorization_code("auth-code", "redirect-uri")
 
+    with pytest.raises(KeycloakError):
+        keycloak_mock.login("username", "password")
+
 
 def test_keycloak_authorization_code(keycloak_mock):
     actual_response = keycloak_mock.authorization_code("auth-code", "redirect-uri")