diff --git a/UNITTESTS/features/lorawan/loraphycn470/Test_LoRaPHYCN470.cpp b/UNITTESTS/features/lorawan/loraphycn470/Test_LoRaPHYCN470.cpp
index 6b6f808fa8..abeefd52d6 100644
--- a/UNITTESTS/features/lorawan/loraphycn470/Test_LoRaPHYCN470.cpp
+++ b/UNITTESTS/features/lorawan/loraphycn470/Test_LoRaPHYCN470.cpp
@@ -190,6 +190,7 @@ TEST_F(Test_LoRaPHYCN470, rx_config)
 TEST_F(Test_LoRaPHYCN470, tx_config)
 {
     tx_config_params_t p;
+    memset(&p, 0, sizeof(p));
     int8_t tx = 0;
     lorawan_time_t time = 0;
     p.tx_power = 9;
diff --git a/UNITTESTS/features/lorawan/lorawantimer/Test_LoRaWANTimer.cpp b/UNITTESTS/features/lorawan/lorawantimer/Test_LoRaWANTimer.cpp
index 80a98460ce..3389de828b 100644
--- a/UNITTESTS/features/lorawan/lorawantimer/Test_LoRaWANTimer.cpp
+++ b/UNITTESTS/features/lorawan/lorawantimer/Test_LoRaWANTimer.cpp
@@ -63,18 +63,21 @@ void my_callback()
 TEST_F(Test_LoRaWANTimer, init)
 {
     timer_event_t ev;
+    memset(&ev, 0, sizeof(ev));
     object->init(ev, my_callback);
 }
 
 TEST_F(Test_LoRaWANTimer, start)
 {
     timer_event_t ev;
+    memset(&ev, 0, sizeof(ev));
     object->start(ev, 10);
 }
 
 TEST_F(Test_LoRaWANTimer, stop)
 {
     timer_event_t ev;
+    memset(&ev, 0, sizeof(ev));
     ev.timer_id = 4;
     object->stop(ev);
     EXPECT_TRUE(ev.timer_id == 0);