diff --git a/cpu/efm32/periph/pm.c b/cpu/efm32/periph/pm.c
index d918fc1114..9c60448cef 100644
--- a/cpu/efm32/periph/pm.c
+++ b/cpu/efm32/periph/pm.c
@@ -22,18 +22,24 @@
 
 #include "em_emu.h"
 
+#define ENABLE_DEBUG 0
+#include "debug.h"
+
 void pm_set(unsigned mode)
 {
     switch (mode) {
         case EFM32_PM_MODE_EM3:
+            DEBUG_PUTS("[pm] enter EFM32_PM_MODE_EM3");
             /* after exiting EM3, clocks are restored */
             EMU_EnterEM3(true);
             break;
         case EFM32_PM_MODE_EM2:
+            DEBUG_PUTS("[pm] enter EFM32_PM_MODE_EM2");
             /* after exiting EM2, clocks are restored */
             EMU_EnterEM2(true);
             break;
         case EFM32_PM_MODE_EM1:
+            DEBUG_PUTS("[pm] enter EFM32_PM_MODE_EM1");
             /* wait for next event or interrupt */
             EMU_EnterEM1();
             break;