diff --git a/epicardium/drivers/sleep.c b/epicardium/drivers/sleep.c
index 21da2ac80aa588814bbb5b5b0809d4edf96ad018..2a367b9fb2a238ee73bf07e0cd1040ba7e626147 100644
--- a/epicardium/drivers/sleep.c
+++ b/epicardium/drivers/sleep.c
@@ -195,6 +195,8 @@ void sleep_deepsleep(void)
 		BbDrvDisable();
 	}
 	turnOffClocks();
+
+	SYS_ClockSourceEnable(SYS_CLOCK_HIRC);
 	old_clkcn = MXC_GCR->clkcn;
 	switchToHIRC();
 	deepsleep();