diff --git a/src/modules/mavlink/mavlink_receiver.cpp b/src/modules/mavlink/mavlink_receiver.cpp
index 2460ec729c..d6090fa4a7 100644
--- a/src/modules/mavlink/mavlink_receiver.cpp
+++ b/src/modules/mavlink/mavlink_receiver.cpp
@@ -2632,48 +2632,55 @@ MavlinkReceiver::Run()
 				}
 			}
 
+			// only start accepting messages on UDP once we're sure who we talk to
+			if (_mavlink->get_protocol() != Protocol::UDP || _mavlink->get_client_source_initialized()) {
 #endif // MAVLINK_UDP
 
-			/* if read failed, this loop won't execute */
-			for (ssize_t i = 0; i < nread; i++) {
-				if (mavlink_parse_char(_mavlink->get_channel(), buf[i], &msg, &_status)) {
+				/* if read failed, this loop won't execute */
+				for (ssize_t i = 0; i < nread; i++) {
+					if (mavlink_parse_char(_mavlink->get_channel(), buf[i], &msg, &_status)) {
 
-					/* check if we received version 2 and request a switch. */
-					if (!(_mavlink->get_status()->flags & MAVLINK_STATUS_FLAG_IN_MAVLINK1)) {
-						/* this will only switch to proto version 2 if allowed in settings */
-						_mavlink->set_proto_version(2);
+						/* check if we received version 2 and request a switch. */
+						if (!(_mavlink->get_status()->flags & MAVLINK_STATUS_FLAG_IN_MAVLINK1)) {
+							/* this will only switch to proto version 2 if allowed in settings */
+							_mavlink->set_proto_version(2);
+						}
+
+						/* handle generic messages and commands */
+						handle_message(&msg);
+
+						/* handle packet with mission manager */
+						_mission_manager.handle_message(&msg);
+
+
+						/* handle packet with parameter component */
+						_parameters_manager.handle_message(&msg);
+
+						if (_mavlink->ftp_enabled()) {
+							/* handle packet with ftp component */
+							_mavlink_ftp.handle_message(&msg);
+						}
+
+						/* handle packet with log component */
+						_mavlink_log_handler.handle_message(&msg);
+
+						/* handle packet with timesync component */
+						_mavlink_timesync.handle_message(&msg);
+
+						/* handle packet with parent object */
+						_mavlink->handle_message(&msg);
 					}
-
-					/* handle generic messages and commands */
-					handle_message(&msg);
-
-					/* handle packet with mission manager */
-					_mission_manager.handle_message(&msg);
-
-
-					/* handle packet with parameter component */
-					_parameters_manager.handle_message(&msg);
-
-					if (_mavlink->ftp_enabled()) {
-						/* handle packet with ftp component */
-						_mavlink_ftp.handle_message(&msg);
-					}
-
-					/* handle packet with log component */
-					_mavlink_log_handler.handle_message(&msg);
-
-					/* handle packet with timesync component */
-					_mavlink_timesync.handle_message(&msg);
-
-					/* handle packet with parent object */
-					_mavlink->handle_message(&msg);
 				}
+
+				/* count received bytes (nread will be -1 on read error) */
+				if (nread > 0) {
+					_mavlink->count_rxbytes(nread);
+				}
+
+#if defined(MAVLINK_UDP)
 			}
 
-			/* count received bytes (nread will be -1 on read error) */
-			if (nread > 0) {
-				_mavlink->count_rxbytes(nread);
-			}
+#endif // MAVLINK_UDP
 		}
 
 		hrt_abstime t = hrt_absolute_time();