1 files changed, 18 insertions, 0 deletions
diff --git a/tests/untried/neg/t663.scala b/tests/untried/neg/t663.scala
new file mode 100644
index 000000000..797c4a300
--- /dev/null
+++ b/tests/untried/neg/t663.scala
@@ -0,0 +1,18 @@
+package test;
+trait Test {
+  type Matchable <: Node with MatchableImpl;
+  trait MatchableImpl extends NodeImpl {
+    def asMatch(node : Matchable) : Any;
+  }
+  type Node <: NodeImpl;
+  trait NodeImpl;
+  trait CoreIfImpl extends MatchableImpl {
+    // NO_CRASH: def asMatch(m : Matchable) = {
+    def asMatch(m : Node) : Any = {
+      if (m.isInstanceOf[MatchableImpl]) {
+        null;
+      } else null;
+      // NO_CRASH: null;
+    }
+  }
+}