diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,14 @@
 
 ## [Unreleased]
 
+## 0.19.0.1 — 2026-10-05
+
+### Other Changes
+
+- Admit effectful 2.7 alongside 2.6: `effectful <2.8` and
+  `effectful-core >=2.6 && <2.7 || >=2.7.1.1 && <2.8`. Exclude the
+  effectful-core 2.7.0.0–2.7.1.0 performance regression. Bounds only; no source changed.
+
 ## 0.19.0.0 — 2026-09-25
 
 ### Breaking Changes
diff --git a/keiro.cabal b/keiro.cabal
--- a/keiro.cabal
+++ b/keiro.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: keiro
-version: 0.19.0.0
+version: 0.19.0.1
 synopsis: Event sourcing framework and workflow engine
 description:
   A library that composes kiroku, keiki, and shibuya into an
@@ -156,8 +156,8 @@
     contravariant-extras >=0.3 && <0.4,
     cryptohash-sha256 >=0.11.102 && <0.12,
     deepseq >=1.5 && <1.6,
-    effectful >=2.6 && <2.7,
-    effectful-core >=2.6 && <2.7,
+    effectful >=2.6 && <2.8,
+    effectful-core >=2.6 && <2.7 || >=2.7.1.1 && <2.8,
     generic-lens >=2.2 && <2.4,
     hasql >=1.10 && <1.11,
     hasql-pool >=1.2 && <1.5,
@@ -167,7 +167,7 @@
     hs-opentelemetry-semantic-conventions >=1.40 && <2,
     keiki >=0.9 && <0.10,
     keiki-codec-json >=0.9 && <0.10,
-    keiro-core ^>=0.19.0.0,
+    keiro-core ^>=0.19.0.1,
     kiroku-store >=0.9.0.1 && <0.10,
     lens >=5.2 && <5.4,
     mmzk-typeid >=0.7 && <0.8,
@@ -219,8 +219,8 @@
     bytestring >=0.11 && <0.13,
     containers >=0.6 && <0.8,
     contravariant-extras >=0.3 && <0.4,
-    effectful >=2.6 && <2.7,
-    effectful-core >=2.6 && <2.7,
+    effectful >=2.6 && <2.8,
+    effectful-core >=2.6 && <2.7 || >=2.7.1.1 && <2.8,
     hasql >=1.10 && <1.11,
     hasql-pool >=1.2 && <1.5,
     hasql-transaction >=1.1 && <1.3,
@@ -233,7 +233,7 @@
     keiki,
     keiki-codec-json,
     keiro,
-    keiro-test-support ^>=0.19.0.0,
+    keiro-test-support ^>=0.19.0.1,
     kiroku-store >=0.9.0.1 && <0.10,
     process >=1.6 && <1.7,
     shibuya-core ^>=0.10.0.0,
@@ -263,14 +263,14 @@
   build-depends:
     aeson >=2.2 && <2.3,
     base >=4.21 && <5,
-    effectful >=2.6 && <2.7,
-    effectful-core >=2.6 && <2.7,
+    effectful >=2.6 && <2.8,
+    effectful-core >=2.6 && <2.7 || >=2.7.1.1 && <2.8,
     hspec >=2.11,
     keiki >=0.9 && <0.10,
     keiki-codec-json >=0.9 && <0.10,
     keiro,
-    keiro-core ^>=0.19.0.0,
-    keiro-test-support ^>=0.19.0.0,
+    keiro-core ^>=0.19.0.1,
+    keiro-test-support ^>=0.19.0.1,
     kiroku-store >=0.9.0.1 && <0.10,
     shibuya-core ^>=0.10.0.0,
     shibuya-kiroku-adapter ^>=0.5.1.5,
@@ -302,7 +302,7 @@
     containers >=0.6 && <0.8,
     deepseq >=1.5 && <1.6,
     directory >=1.3 && <1.4,
-    effectful >=2.6 && <2.7,
+    effectful >=2.6 && <2.8,
     filepath >=1.4 && <1.6,
     hasql >=1.10 && <1.11,
     hasql-transaction >=1.1 && <1.3,
@@ -310,8 +310,8 @@
     hs-opentelemetry-sdk >=1.0 && <1.1,
     keiki >=0.9 && <0.10,
     keiro,
-    keiro-core ^>=0.19.0.0,
-    keiro-test-support ^>=0.19.0.0,
+    keiro-core ^>=0.19.0.1,
+    keiro-test-support ^>=0.19.0.1,
     kiroku-store >=0.9.0.1 && <0.10,
     shibuya-core ^>=0.10.0.0,
     streamly-core >=0.3 && <0.4,