diff --git a/ExtLibs/ArduPilot/Mavlink/MAVLinkInterface.cs b/ExtLibs/ArduPilot/Mavlink/MAVLinkInterface.cs
index e3ac888075..4ceb202f1e 100644
--- a/ExtLibs/ArduPilot/Mavlink/MAVLinkInterface.cs
+++ b/ExtLibs/ArduPilot/Mavlink/MAVLinkInterface.cs
@@ -733,7 +733,7 @@ private void OpenBg(IProgressReporterDialogue PRsender, bool getparams)
                 var countDown = new Timer {Interval = 1000, AutoReset = false};
                 countDown.Elapsed += (sender, e) =>
                 {
-                    int secondsRemaining = (deadline - e.SignalTime).Seconds;
+                    int secondsRemaining = Convert.ToInt32((deadline - e.SignalTime).TotalSeconds);
                     frmProgressReporter.UpdateProgressAndStatus(-1, string.Format(Strings.Trying, secondsRemaining));
                     if (secondsRemaining > 0) countDown.Start();
                 };