diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index 79a69b88b2962..4d6f1e164ccc9 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -1619,7 +1619,7 @@ void AP_GPS::handle_gps_rtcm_data(mavlink_channel_t chan, const mavlink_message_
  */
 bool AP_GPS::parse_rtcm_injection(mavlink_channel_t chan, const mavlink_gps_rtcm_data_t &pkt)
 {
-    if (chan >= MAVLINK_COMM_NUM_BUFFERS) {
+    if (static_cast<int>(chan) >= MAVLINK_COMM_NUM_BUFFERS) {
         return false;
     }
     if (rtcm.parsers[chan] == nullptr) {
diff --git a/libraries/GCS_MAVLink/GCS_MAVLink.h b/libraries/GCS_MAVLink/GCS_MAVLink.h
index b59ba9d93c311..7a7db6a68366a 100644
--- a/libraries/GCS_MAVLink/GCS_MAVLink.h
+++ b/libraries/GCS_MAVLink/GCS_MAVLink.h
@@ -55,10 +55,7 @@ extern mavlink_system_t mavlink_system;
 /// @param chan		Channel to send to
 static inline bool valid_channel(mavlink_channel_t chan)
 {
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wtautological-constant-out-of-range-compare"
-    return chan < MAVLINK_COMM_NUM_BUFFERS;
-#pragma clang diagnostic pop
+    return static_cast<int>(chan) < MAVLINK_COMM_NUM_BUFFERS;
 }
 
 mavlink_message_t* mavlink_get_channel_buffer(uint8_t chan);