diff --git a/testcases/regression/unifier_valid.scala b/testcases/regression/unifier_valid.scala
index 6fa6c41f148c64346a15f575fc302e9af70552cf..d201527ceebf5f62088fbb3ba38d37b737f642bf 100644
--- a/testcases/regression/unifier_valid.scala
+++ b/testcases/regression/unifier_valid.scala
@@ -26,7 +26,7 @@ object BinarySearchTree {
         n
       }
     }
-  } //ensuring (contents(_) == contents(tree) ++ Set(value))
+  } ensuring (contents(_) == contents(tree) ++ Set(value))
 
 
   def dumbInsert(tree: Tree): Node = {