Fixes #4723.

Review by extempore.

2 files changed, 10 insertions, 1 deletions

diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala
index 1781e7ba36..7d962d2908 100644
--- a/src/library/scala/collection/immutable/List.scala
+++ b/src/library/scala/collection/immutable/List.scala
@@ -374,7 +374,7 @@ case object Nil extends List[Nothing] {
     throw new UnsupportedOperationException("tail of empty list")
   // Removal of equals method here might lead to an infinite recursion similar to IntMap.equals.
   override def equals(that: Any) = that match {
-    case that1: collection.Seq[_] => that1.isEmpty
+    case that1: collection.GenSeq[_] => that1.isEmpty
     case _ => false
   }
 }
diff --git a/test/files/run/t4723.scala b/test/files/run/t4723.scala
new file mode 100644
index 0000000000..4278ff9aaf
--- /dev/null
+++ b/test/files/run/t4723.scala
@@ -0,0 +1,9 @@
+
+
+
+object Test {
+  def main(args: Array[String]) {
+    assert(Nil == collection.parallel.ParSeq())
+    assert(collection.parallel.ParSeq() == Nil)
+  }
+}