diff --git a/real_system_state.h b/real_system_state.h
index 72a07ad..42d1509 100644
--- a/real_system_state.h
+++ b/real_system_state.h
@@ -7,6 +7,7 @@
 
 #include <update_engine/system_state.h>
 
+#include <update_engine/clock.h>
 #include <update_engine/connection_manager.h>
 #include <update_engine/gpio_handler.h>
 #include <update_engine/payload_state.h>
@@ -34,6 +35,10 @@
     return device_policy_;
   }
 
+  virtual inline ClockInterface* clock() {
+    return &clock_;
+  }
+
   virtual inline ConnectionManager* connection_manager() {
     return &connection_manager_;
   }
@@ -73,6 +78,9 @@
   bool Initialize(bool enable_gpio);
 
 private:
+  // Interface for the clock.
+  Clock clock_;
+
   // The latest device policy object from the policy provider.
   const policy::DevicePolicy* device_policy_;