diff --git a/real_system_state.h b/real_system_state.h
index 071e3e0..13fbfad 100644
--- a/real_system_state.h
+++ b/real_system_state.h
@@ -20,6 +20,7 @@
 #include "update_engine/system_state.h"
 
 #include <memory>
+#include <set>
 
 #include <debugd/dbus-proxies.h>
 #include <metrics/metrics_library.h>
@@ -63,6 +64,10 @@
 
   void AddObserver(ServiceObserverInterface* observer) override;
   void RemoveObserver(ServiceObserverInterface* observer) override;
+  const std::set<ServiceObserverInterface*>& service_observers() override {
+    CHECK(update_attempter_.get());
+    return update_attempter_->service_observers();
+  }
 
   // SystemState overrides.
   inline void set_device_policy(