1 files changed, 2 insertions, 0 deletions
diff --git a/src/scope.h b/src/scope.h
index 88b45d84..8c98bb3d 100644
--- a/src/scope.h
+++ b/src/scope.h
@@ -157,9 +157,11 @@ public:
   }
 
   void set_args(const value_t& _args) {
+    assert(_args.is_sequence());
     args = _args;
   }
   value_t& value() {
+    assert(args.is_null() || args.is_sequence());
     return args;
   }