diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,16 @@
 [Keep a Changelog](https://keepachangelog.com/), and the package follows the
 [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
-## [Unreleased]
+## [0.11.0.0] - 2026-08-05
+
+### Breaking Changes
+
+- Requires `keiki >=0.9 && <0.10`, replacing `>=0.8 && <0.9`. Keiki 0.9
+  classifies trusted event heads by structural constructor evidence and can
+  prove some integral register/literal replay candidates disjoint, so
+  `validateEventStream` and `mkEventStream` may return a different conservative
+  inversion-ambiguity warning set. The `EventStreamWarning` API and runtime
+  stepping/replay behavior are unchanged.
 
 ## 0.10.0.0 — 2026-08-03
 
diff --git a/keiro-core.cabal b/keiro-core.cabal
--- a/keiro-core.cabal
+++ b/keiro-core.cabal
@@ -1,6 +1,6 @@
 cabal-version:   3.0
 name:            keiro-core
-version:         0.10.0.0
+version:         0.11.0.0
 synopsis:        Core contracts for Keiro packages
 description:
   Stable stream, codec, event-stream, and integration-event contracts
@@ -61,7 +61,7 @@
     , bytestring    >=0.11 && <0.13
     , deepseq       >=1.5  && <1.6
     , generic-lens  >=2.2  && <2.4
-    , keiki         >=0.8  && <0.9
+    , keiki         >=0.9  && <0.10
     , kiroku-store  >=0.3  && <0.4
     , lens          >=5.2  && <5.4
     , mmzk-typeid   >=0.7  && <0.8