diff --git a/docs/memory-system/03-architecture-decisions.md b/docs/memory-system/03-architecture-decisions.md
index 6d4b59a..07daeb3 100644
--- a/docs/memory-system/03-architecture-decisions.md
+++ b/docs/memory-system/03-architecture-decisions.md
@@ -1,3 +1,6 @@
+---
+hygiene: frozen
+---
 # Architecture Decision Records
 
 _Last updated: 2026-07-10_