diff --git a/CHANGELOG.md b/CHANGELOG.md
index 06295c3..9eb539e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,21 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ---
 
+## [0.2.9] — 2026-07-21
+
+### Changed
+- **measure-mirror pin `28290f2` → `abe0c19` (v0.28.0 → v0.28.1)**. Picks up the
+  **`power_check` honesty fix**: the probe hardcoded its critical values
+  (`z_alpha2 = 1.96`, `z_beta = 0.842`), so `mm_power_check` printed the
+  requested power (e.g. "at 99% power") while the required-n was *always*
+  computed at 80% power / α=0.05 — the printed text and number contradicted
+  each other. Both z-values now derive from the `alpha`/`target_power`
+  arguments via `statistics.NormalDist().inv_cdf` (stdlib, still zero-dep);
+  `target_power=0.99` → n≥1829 (was 781), `alpha=0.0001` → n≥2229. Default
+  (α=0.05, power=0.80) unchanged. This reaches the `mm_power_check` tool.
+- Pin recorded as the **full 40-hex SHA** (the v0.28.0 bump #20 landed a 9-hex
+  abbreviation, which broke the cross-repo pin-lag checker; normalized since).
+
 ## [0.2.8] — 2026-07-21
 
 ### Changed
diff --git a/mirror_stack_mcp/__init__.py b/mirror_stack_mcp/__init__.py
index 72c20c1..8c661ad 100644
--- a/mirror_stack_mcp/__init__.py
+++ b/mirror_stack_mcp/__init__.py
@@ -1,2 +1,2 @@
 """🪞🔎🪪 Mirror Stack unified MCP server."""
-__version__ = "0.2.8"
+__version__ = "0.2.9"
diff --git a/pyproject.toml b/pyproject.toml
index 34eb87b..6e8fe70 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "mirror-stack-mcp"
-version = "0.2.8"
+version = "0.2.9"
 description = "Unified MCP server for the Mirror Stack — claims, actions, provenance + verify-all in one server"
 readme = "README.md"
 requires-python = ">=3.10"
@@ -16,7 +16,7 @@ dependencies = [
     # tracks each mirror's default branch, so an install made before a mirror's release
     # freezes on whatever was HEAD then and never refreshes — that is how a local install
     # ran stale measure-mirror 0.14.3 long after 0.15.1 landed. Bump these on purpose.
-    "measure-mirror @ git+https://github.com/mirror-stack/measure-mirror@28290f2bad327525a0ec3b0b6287805c684c4647",   # v0.28.0 — SECURITY: verify_chain no longer waives the chain link on missing prev_seal (SPEC §4 rule 3); v0.27.0 full 64-hex seals; v0.26 ㉗ prereg_lint
+    "measure-mirror @ git+https://github.com/mirror-stack/measure-mirror@abe0c19d3894c1278a9bf5281a45946ef0e1eea4",   # v0.28.1 — power_check honors alpha/target_power (was hardcoded 1.96/0.842: text-vs-number lie); v0.28.0 SECURITY verify_chain prev_seal (SPEC §4 rule 3); v0.27.0 full 64-hex seals; v0.26 ㉗ prereg_lint
     "action-mirror @ git+https://github.com/mirror-stack/action-mirror@fa1fc4998936e6bf179b5c14825fb09e78a36087",     # v0.2.0 — full 64-hex SHA-256 seals (security; legacy 16-hex verify via prefix match); v0.1.0 ledgers conform to MIRROR-SPEC v1.0
     "provenance-mirror @ git+https://github.com/mirror-stack/provenance-mirror@321f84abc4ffd91da43a5ebc866b5ce02cf3c276",  # v0.2.0 — full 64-hex SHA-256 seals (security; legacy 16-hex verify via prefix match); v0.1.0 ledgers conform to MIRROR-SPEC v1.0
 ]