diff --git a/openspec/changes/complete-encoded-frame-transport/tasks.md b/openspec/changes/complete-encoded-frame-transport/tasks.md
index 21960cd..5be5f91 100644
--- a/openspec/changes/complete-encoded-frame-transport/tasks.md
+++ b/openspec/changes/complete-encoded-frame-transport/tasks.md
@@ -15,4 +15,6 @@
 
 ## 4. Immutable boundary
 
-- [ ] 4.1 Publish one new never-reused immutable Protocol version and resolve it from empty consumer caches
+- [x] 4.1 Publish one new never-reused immutable Protocol version, resolve it
+  from separate empty consumer caches, and pin the fetched checksums in both
+  consumers