diff --git a/tests/pos/18789.scala b/tests/pos/18789.scala
new file mode 100644
index 000000000000..28ddfd56305d
--- /dev/null
+++ b/tests/pos/18789.scala
@@ -0,0 +1,4 @@
+sealed trait TypeId:
+  case class Foo() extends TypeId
+
+object TypeId {}