diff --git a/tests/pos/i19633.scala b/tests/pos/i19633.scala
new file mode 100644
index 000000000000..d0c6a45b5f0a
--- /dev/null
+++ b/tests/pos/i19633.scala
@@ -0,0 +1,24 @@
+object Repro {
+  trait Responsive {
+    type Response
+  }
+
+  object Responsive {
+    type Aux[R] = Responsive {type Response = R}
+    type Response[R] = R match {case Aux[r] => r}
+  }
+
+  case class StringRequest(name: String) extends Responsive {
+    type Response = String
+  }
+
+  def withImplicit[R <: Responsive](request: R)(implicit ct: scala.reflect.ClassTag[Responsive.Response[R]]): Responsive.Response[R] = ???
+
+  def withFunction[R <: Responsive](request: R)(call: R => Responsive.Response[R]): Responsive.Response[R] = ???
+
+  def stringWithFunction(req: StringRequest): String = withFunction(req)(_.getClass.getSimpleName)
+
+  def stringWithImplicit(req: StringRequest): String = withImplicit(req)
+
+  def main(args: Array[String]): Unit = {}
+}