diff --git a/tests/driver_adcxx1c/main.c b/tests/driver_adcxx1c/main.c
index 2cc6fb4ad9..a06691f72b 100644
--- a/tests/driver_adcxx1c/main.c
+++ b/tests/driver_adcxx1c/main.c
@@ -30,6 +30,7 @@ static adcxx1c_t dev;
 
 static void alert_cb(void *arg)
 {
+    (void)arg;
     puts("[Alert]\n");
 }