diff --git a/cpu/samd21/include/periph_cpu.h b/cpu/samd21/include/periph_cpu.h
index 608ba468be..69b8e8272f 100644
--- a/cpu/samd21/include/periph_cpu.h
+++ b/cpu/samd21/include/periph_cpu.h
@@ -32,7 +32,7 @@ extern "C" {
  * @brief   Override the default initial PM blocker
  * @todo   Idle modes are enabled by default, deep sleep mode blocked
  */
-#define PM_BLOCKER_INITIAL  { .val_u32 = 0x00000001 }
+#define PM_BLOCKER_INITIAL      0x00000001
 
 /**
  * @name   SAMD21 sleep modes for PM
diff --git a/cpu/saml1x/include/periph_cpu.h b/cpu/saml1x/include/periph_cpu.h
index 1732b3ff6b..93eb7bb9b5 100644
--- a/cpu/saml1x/include/periph_cpu.h
+++ b/cpu/saml1x/include/periph_cpu.h
@@ -30,7 +30,7 @@ extern "C" {
  * @brief   Override the default initial PM blocker
  * @todo   Idle modes are enabled by default, deep sleep mode blocked
  */
-#define PM_BLOCKER_INITIAL  { .val_u32 = 0x00000001 }
+#define PM_BLOCKER_INITIAL  0x00000001
 
 /**
  * @name   SAML1x GCLK definitions