diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/App.config b/tests/Avalonia.Markup.Xaml.UnitTests/App.config
new file mode 100644
index 0000000000..1cdd157954
--- /dev/null
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/App.config
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <system.diagnostics>
+    <assert assertuienabled="false"/>
+  </system.diagnostics>
+</configuration>