diff --git a/tests/neg/i12640.scala b/tests/neg/i12640.scala
deleted file mode 100644
index 7946525deeeb..000000000000
--- a/tests/neg/i12640.scala
+++ /dev/null
@@ -1,17 +0,0 @@
-package x
-
-trait CpsMonad[F[_]]:
-  def pure[A](x:A): F[A]
-  def flatMap[A,B](fa:F[A])(f: A=>F[B]): F[B]
-
-abstract sealed class CpsStream[-F[_],+T]
-
-case class Cons[F[_],T](head:T, tailFun: ()=>F[CpsStream[F,T]]) extends CpsStream[F,T]
-
-case class Empty[F[_]]() extends CpsStream[F,Nothing]
-
-def unfold[S,F[_]:CpsMonad,T](s0:S)(f:S => F[Option[(S,T)]]):F[CpsStream[F,T]] =
-      summon[CpsMonad[F]].flatMap(f(s0)){
-         case Some(s1,a) => Cons(a, () => unfold(s1,f))  // error // error
-         case None => summon[CpsMonad[F]].pure(Empty[F]())
-      }
\ No newline at end of file