diff --git a/examples/lorawan/main.c b/examples/lorawan/main.c
index 7bb6d0671c1b..ff7f99432ed5 100644
--- a/examples/lorawan/main.c
+++ b/examples/lorawan/main.c
@@ -154,7 +154,7 @@ int main(void)
      * in general provides RAM retention after wake-up.
      */
 #if IS_USED(MODULE_PM_LAYERED)
-    for (unsigned i = 1; i < PM_NUM_MODES; ++i) {
+    for (unsigned i = 1; i < PM_NUM_MODES - 1; ++i) {
         pm_unblock(i);
     }
 #endif
diff --git a/pkg/openwsn/contrib/board.c b/pkg/openwsn/contrib/board.c
index 1d57838ac8c1..262a020c59f2 100644
--- a/pkg/openwsn/contrib/board.c
+++ b/pkg/openwsn/contrib/board.c
@@ -49,8 +49,8 @@ void board_init_openwsn(void)
     LOG_DEBUG("[openwsn/board]: init\n");
 
 #ifdef MODULE_PM_LAYERED
-    /* sleeping is currently not supported, block all sleep modes */
-    for (uint8_t i = 0; i < PM_NUM_MODES; i++) {
+    /* sleeping is currently not supported, block all sleep modes except IDLE */
+    for (uint8_t i = 0; i < PM_NUM_MODES - 1; i++) {
         pm_block(i);
     }
 #endif