diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0040969..fb1fb93 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ghc: ["8.4", "8.6", "8.8", "8.10", "9.0", "9.2", "9.4", "9.6", "9.8", "9.10"]
+        ghc: ["8.4", "8.6", "8.8", "8.10", "9.0", "9.2", "9.4", "9.6", "9.8", "9.10", "9.12"]
 
     steps:
     - uses: actions/checkout@v4
diff --git a/ChangeLog.md b/ChangeLog.md
index b6dcb75..07a8eb1 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,8 @@
+# 0.0.0.9
+
+- Further loosen the bound on `containers`.
+- Support for GHC 9.12.
+
 # 0.0.0.8
 
 Loosen the bound on `containers`.
diff --git a/semilattices.cabal b/semilattices.cabal
index 904ee11..7aad2e2 100644
--- a/semilattices.cabal
+++ b/semilattices.cabal
@@ -1,7 +1,7 @@
 cabal-version:       3.0
 
 name:                semilattices
-version:             0.0.0.8
+version:             0.0.0.9
 synopsis:            Semilattices
 description:         Join- and meet-semilattices, with optional upper and lower bounds, and a variety of instances for each.
 homepage:            https://github.com/robrix/semilattices
@@ -67,7 +67,7 @@ library
     Data.Semilattice.Upper
   build-depends:
     , base >=4.9 && <5
-    , containers >=0.5 && <0.8
+    , containers >=0.5 && <0.9
     , unordered-containers >=0.2.20 && <0.3
   hs-source-dirs:      src
   default-language:    Haskell2010