diff --git a/include/utils/SystemClock.h b/include/utils/SystemClock.h
index 7c319be..d75264c 100644
--- a/include/utils/SystemClock.h
+++ b/include/utils/SystemClock.h
@@ -25,6 +25,7 @@
 int setCurrentTimeMillis(int64_t millis);
 int64_t uptimeMillis();
 int64_t elapsedRealtime();
+int64_t elapsedRealtimeNano();
 
 }; // namespace android
 
diff --git a/include/utils/Timers.h b/include/utils/Timers.h
index 8b4d322..92f66c9 100644
--- a/include/utils/Timers.h
+++ b/include/utils/Timers.h
@@ -78,9 +78,10 @@
     SYSTEM_TIME_REALTIME = 0,  // system-wide realtime clock
     SYSTEM_TIME_MONOTONIC = 1, // monotonic time since unspecified starting point
     SYSTEM_TIME_PROCESS = 2,   // high-resolution per-process clock
-    SYSTEM_TIME_THREAD = 3     // high-resolution per-thread clock
+    SYSTEM_TIME_THREAD = 3,    // high-resolution per-thread clock
+    SYSTEM_TIME_BOOTTIME = 4   // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
 };
-    
+
 // return the system-time according to the specified clock
 #ifdef __cplusplus
 nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);