diff --git a/src/framework/GuiUnit/TestRunner.cs b/src/framework/GuiUnit/TestRunner.cs
index d7d7a10..3950cf3 100644
--- a/src/framework/GuiUnit/TestRunner.cs
+++ b/src/framework/GuiUnit/TestRunner.cs
@@ -242,6 +242,7 @@ void ExecuteWithListener (string[] args, TcpWriter tcpWriter)
 				catch (Exception ex)
 				{
 					writer.WriteLine(ex.ToString());
+					ExitCode = 1;
 				}
 				finally
 				{