diff --git a/hermes_cli/config.py b/hermes_cli/config.py
index b64086c91..cc29e1d56 100644
--- a/hermes_cli/config.py
+++ b/hermes_cli/config.py
@@ -1315,7 +1315,7 @@ DEFAULT_CONFIG = {
                                       # exact route is affected — gpt-5.5 on OpenAI's
                                       # direct API, OpenRouter, and Copilot keep the
                                       # global threshold regardless.
-        "in_place": False,            # When True, compaction rewrites the message
+        "in_place": True,             # When True, compaction rewrites the message
                                       # list and rebuilds the system prompt WITHOUT
                                       # rotating the session id — the conversation
                                       # keeps one durable id for its whole life