diff --git a/cpu/saml21/periph/pm.c b/cpu/saml21/periph/pm.c
index 4d390a8d23..107c520f1a 100644
--- a/cpu/saml21/periph/pm.c
+++ b/cpu/saml21/periph/pm.c
@@ -26,16 +26,19 @@
 
 void pm_set(unsigned mode)
 {
+    int deep = 0;
     uint32_t _mode;
 
     switch (mode) {
         case 0:
             DEBUG_PUTS("pm_set(): setting BACKUP mode.");
             _mode = PM_SLEEPCFG_SLEEPMODE_BACKUP;
+            deep  = 1;
             break;
         case 1:
             DEBUG_PUTS("pm_set(): setting STANDBY mode.");
             _mode = PM_SLEEPCFG_SLEEPMODE_STANDBY;
+            deep  = 1;
             break;
         default: /* Falls through */
         case 2:
@@ -53,5 +56,5 @@ void pm_set(unsigned mode)
     /* make sure value has been set */
     while (PM->SLEEPCFG.bit.SLEEPMODE != _mode) {}
 
-    sam0_cortexm_sleep(0);
+    sam0_cortexm_sleep(deep);
 }