2 files changed, 17 insertions, 0 deletions
diff --git a/test/files/pos/t4911.flags b/test/files/pos/t4911.flags
new file mode 100644
index 0000000000..779916d58f
--- /dev/null
+++ b/test/files/pos/t4911.flags
@@ -0,0 +1 @@
+-unchecked -Xfatal-warnings
+\ No newline at end of file
diff --git a/test/files/pos/t4911.scala b/test/files/pos/t4911.scala
new file mode 100644
index 0000000000..66c867a37f
--- /dev/null
+++ b/test/files/pos/t4911.scala
@@ -0,0 +1,16 @@
+import language._
+
+object Test {
+  class Foo[T](val x: T) ; object Foo { def unapply[T](x: Foo[T]) = Some(x.x) }
+  def f1[T](x: Foo[T]) = x match { case Foo(y) => y }
+  def f2[M[_], T](x: M[T]) = x match { case Foo(y) => y }
+
+  case class Bar[T](x: T)
+  def f3[T](x: Bar[T]) = x match { case Bar(y) => y }
+  def f4[M[_], T](x: M[T]) = x match { case Bar(y) => y }
+}
+//
+// ./b.scala:4: warning: non variable type-argument T in type pattern Test.Foo[T] is unchecked since it is eliminated by erasure
+//   def f2[M[_], T](x: M[T]) = x match { case Foo(y) => y }
+//                                                ^
+// one warning found
+\ No newline at end of file