diff --git a/system_state.h b/system_state.h
index 56d38a6..08092f1 100644
--- a/system_state.h
+++ b/system_state.h
@@ -19,6 +19,7 @@
 // the required classes.
 class ClockInterface;
 class ConnectionManager;
+class HardwareInterface;
 class PrefsInterface;
 class PayloadStateInterface;
 class GpioHandler;
@@ -54,6 +55,9 @@
   // Gets the connection manager object.
   virtual ConnectionManager* connection_manager() = 0;
 
+  // Gets the hardware interface object.
+  virtual HardwareInterface* hardware() = 0;
+
   // Gets the Metrics Library interface for reporting UMA stats.
   virtual MetricsLibraryInterface* metrics_lib() = 0;