diff --git a/goesrecv-monitor/Stats.cs b/goesrecv-monitor/Stats.cs
index e26ebd8..26af6b5 100644
--- a/goesrecv-monitor/Stats.cs
+++ b/goesrecv-monitor/Stats.cs
@@ -236,7 +236,7 @@ static void DecoderLoop()
 
                         if (rsStr != "-1")
                         {
-                            rsErr += int.Parse(rsStr);
+                            int.TryParse(rsStr, out rsErr);
                         }
                     }
                 }