diff --git a/test/Microsoft.AspNetCore.Razor.Design.Test/xunit.runner.json b/test/Microsoft.AspNetCore.Razor.Design.Test/xunit.runner.json
index fcf172c8fc..d00e4ae907 100644
--- a/test/Microsoft.AspNetCore.Razor.Design.Test/xunit.runner.json
+++ b/test/Microsoft.AspNetCore.Razor.Design.Test/xunit.runner.json
@@ -1,4 +1,5 @@
 {
   "methodDisplay": "method",
-  "shadowCopy": false
+  "shadowCopy": false,
+  "maxParallelThreads": -1
 }
\ No newline at end of file