diff --git a/pkg/semtech-loramac/contrib/semtech_loramac_timer.c b/pkg/semtech-loramac/contrib/semtech_loramac_timer.c
index 346bc7fe93..1725262f2d 100644
--- a/pkg/semtech-loramac/contrib/semtech_loramac_timer.c
+++ b/pkg/semtech-loramac/contrib/semtech_loramac_timer.c
@@ -27,7 +27,10 @@ extern kernel_pid_t semtech_loramac_pid;
 
 void TimerInit(TimerEvent_t *obj, void (*cb)(void))
 {
-    obj->dev.target = 0;
+    obj->dev.start_time = 0;
+    obj->dev.long_start_time = 0;
+    obj->dev.offset = 0;
+    obj->dev.long_offset = 0;
     obj->running = 0;
     obj->cb = cb;
 }