diff --git a/xo-interpreter2/src/skrepl/skreplxx.cpp b/xo-interpreter2/src/skrepl/skreplxx.cpp
index e3d5564e..86ab461a 100644
--- a/xo-interpreter2/src/skrepl/skreplxx.cpp
+++ b/xo-interpreter2/src/skrepl/skreplxx.cpp
@@ -88,7 +88,7 @@ namespace xo {
 
         AppConfig(const ReplConfig & repl_cfg = ReplConfig(),
                   const ArenaConfig & app_arena_cfg = ArenaConfig().with_name("skreplxx").with_size(16 * 1024),
-                  const VsmConfig & vsm_cfg = VsmConfig())
+                  const VsmConfig & vsm_cfg = VsmConfig().with_x1_debug_flag(true))
         : repl_config_{repl_cfg}, app_arena_config_{app_arena_cfg}, vsm_config_{vsm_cfg}
         {
             //rdr_config_.reader_debug_flag_ = true;