diff --git a/libraries/mbed/targets/hal/TARGET_NORDIC/TARGET_NRF51822/sleep.c b/libraries/mbed/targets/hal/TARGET_NORDIC/TARGET_NRF51822/sleep.c
index 5a0c4780c2..344b978fee 100644
--- a/libraries/mbed/targets/hal/TARGET_NORDIC/TARGET_NRF51822/sleep.c
+++ b/libraries/mbed/targets/hal/TARGET_NORDIC/TARGET_NRF51822/sleep.c
@@ -21,10 +21,10 @@ void sleep(void) {
     // ensure debug is disconnected if semihost is enabled....
     NRF_POWER->TASKS_LOWPWR=1;
     // wait for interrupt
-    __WFI();
+    __WFE();
 }
 
 void deepsleep(void) {
     sleep();
-    NRF_POWER->SYSTEMOFF=1;
+ //   NRF_POWER->SYSTEMOFF=1;
 }