diff --git a/stub_ui.h b/stub_ui.h
index 2ccd491..fddf4e7 100644
--- a/stub_ui.h
+++ b/stub_ui.h
@@ -28,6 +28,9 @@
  public:
   StubRecoveryUI() = default;
 
+  std::string GetLocale() override {
+    return "";
+  }
   void SetBackground(Icon /* icon */) override {}
   void SetSystemUpdateText(bool /* security_update */) override {}