diff --git a/cpukit/score/include/rtems/score/timecounter.h b/cpukit/score/include/rtems/score/timecounter.h
index 33de269ec8..f00a33ba70 100644
--- a/cpukit/score/include/rtems/score/timecounter.h
+++ b/cpukit/score/include/rtems/score/timecounter.h
@@ -208,6 +208,13 @@ extern volatile time_t _Timecounter_Time_second;
  */
 extern volatile time_t _Timecounter_Time_uptime;
 
+/**
+ * @brief The binary boot time.
+ *
+ * The boot time changes via _Timecounter_Set_clock().
+ */
+extern struct bintime _Timecounter_Boottimebin;
+
 /**
  * @brief The current timecounter.
  */