diff --git a/core/src/test/scala-3/cats/derived/adtdefns.scala b/core/src/test/scala-3/cats/derived/adtdefns.scala
index 62681f95..215e6146 100644
--- a/core/src/test/scala-3/cats/derived/adtdefns.scala
+++ b/core/src/test/scala-3/cats/derived/adtdefns.scala
@@ -217,6 +217,8 @@ object TestDefns:
   final case class IntLeaf(t: Int) extends IntTree
   final case class IntNode(l: IntTree, r: IntTree) extends IntTree
 
+  object IntTree
+
   sealed trait GenericAdt[A]
   final case class GenericAdtCase[A](value: Option[A]) extends GenericAdt[A]