diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 529b133fd..54736c816 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "8.1.0"
+  ".": "8.1.1"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1fe6c55df..fc2175048 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,13 @@
   [migration guide](docs/canonical-format-kinds-migration.md).
   This closes [#1241](https://github.com/adcontextprotocol/adcp-client-python/issues/1241).
 
+## [8.1.1](https://github.com/adcontextprotocol/adcp-client-python/compare/v8.1.0...v8.1.1) (2026-10-08)
+
+
+### Bug Fixes
+
+* **protocol:** adopt the signed AdCP 3.2.3 security bundle ([#1429](https://github.com/adcontextprotocol/adcp-client-python/issues/1429)) ([d739088](https://github.com/adcontextprotocol/adcp-client-python/commit/d7390884d2aa0133e4845aac3f7bb80fc17d1cee))
+
 ## [8.1.0](https://github.com/adcontextprotocol/adcp-client-python/compare/v8.0.0...v8.1.0) (2026-10-06)
 
 
diff --git a/pyproject.toml b/pyproject.toml
index d1c21002f..5a07bbb1e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "adcp"
-version = "8.1.0"
+version = "8.1.1"
 description = "Official Python client for the Ad Context Protocol (AdCP)"
 authors = [
     {name = "AdCP Community", email = "maintainers@adcontextprotocol.org"}