diff --git a/ExternalMonitoringUnit.cs b/ExternalMonitoringUnit.cs
index b613121..4b946e8 100644
--- a/ExternalMonitoringUnit.cs
+++ b/ExternalMonitoringUnit.cs
@@ -59,7 +59,14 @@ namespace Barsik
 					float resultFloat;
 					if (float.TryParse(result, out resultFloat))
 					{
-						registers.SetFloat(baseAddress, resultFloat);
+						if (float.IsNaN(resultFloat) || float.IsInfinity(resultFloat))
+						{
+							logger.Error("Nan or Inf received from " + program + " with args " + args);
+						}
+						else
+						{
+							registers.SetFloat(baseAddress, resultFloat);
+						}
 					}
 					else
 					{