diff --git a/tests/generics/tgenerics_various.nim b/tests/generics/tgenerics_various.nim
index 37b6e43a15..4cfa478091 100644
--- a/tests/generics/tgenerics_various.nim
+++ b/tests/generics/tgenerics_various.nim
@@ -262,3 +262,8 @@ proc doSomething[A, B](t: tuple[a: A, b: B]) = discard
 
 discard identity((c: 1, d: 2))
 doSomething(identity((1, 2)))
+
+# bug #6231
+proc myProc[T, U](x: T or U) = discard
+
+myProc[int, string](x = 2)