Index: firmware/powermgmt.c
===================================================================
--- firmware/powermgmt.c	(revision 31266)
+++ firmware/powermgmt.c	(working copy)
@@ -64,6 +64,7 @@
 
 static bool sleeptimer_active = false;
 static long sleeptimer_endtick;
+static unsigned int sleeptimer_duration = 0;
 
 #if CONFIG_CHARGING
 /* State of the charger input as seen by the power thread */
@@ -707,6 +708,8 @@
 void reset_poweroff_timer(void)
 {
     last_event_tick = current_tick;
+    if (sleeptimer_active)
+        set_sleep_timer(sleeptimer_duration);
 }
 
 void sys_poweroff(void)
@@ -772,10 +775,12 @@
     if (seconds) {
         sleeptimer_active  = true;
         sleeptimer_endtick = current_tick + seconds * HZ;
+        sleeptimer_duration = seconds;
     }
     else {
         sleeptimer_active  = false;
         sleeptimer_endtick = 0;
+        sleeptimer_duration = 0;
     }
 }