diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 98df555..0aa0577 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -34,6 +34,7 @@ jobs:
           - "9.6.3"
           - "9.8.1"
           - "9.10.1"
+          - "9.12.1"
 
     steps:
     - uses: actions/checkout@v4
diff --git a/bluefin-internal/bluefin-internal.cabal b/bluefin-internal/bluefin-internal.cabal
index dfde9e3..483ea26 100644
--- a/bluefin-internal/bluefin-internal.cabal
+++ b/bluefin-internal/bluefin-internal.cabal
@@ -78,7 +78,7 @@ library
     hs-source-dirs: src
     build-depends:
       async >= 2.2 && < 2.3,
-      base >= 4.12 && < 4.21,
+      base >= 4.12 && < 4.22,
       unliftio-core < 0.3,
       transformers < 0.7,
       transformers-base < 0.5,