diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp
index a6df1a2eaaf..565a57ca975 100644
--- a/src/modules/mavlink/mavlink_main.cpp
+++ b/src/modules/mavlink/mavlink_main.cpp
@@ -1150,7 +1150,7 @@ Mavlink::find_broadcast_address()
 			const struct in_addr netmask_addr = query_netmask_addr(_socket_fd, *cur_ifreq);
 			const struct in_addr broadcast_addr = compute_broadcast_addr(sin_addr, netmask_addr);
 
-			if (_interface_name && strstr(cur_ifreq->ifr_name, _interface_name) == NULL) { continue; }
+			if (_interface_name && strstr(cur_ifreq->ifr_name, _interface_name) == nullptr) { continue; }
 
 			PX4_INFO("using network interface %s, IP: %s", cur_ifreq->ifr_name, inet_ntoa(sin_addr));
 			PX4_INFO("with netmask: %s", inet_ntoa(netmask_addr));