diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 092f7a6..1a5a6f3 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -8,9 +8,9 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.19.20250821
+# version: 0.19.20251211
 #
-# REGENDATA ("0.19.20250821",["github","generic-data.cabal"])
+# REGENDATA ("0.19.20251211",["github","generic-data.cabal"])
 #
 name: Haskell-CI
 on:
@@ -20,6 +20,9 @@ on:
   pull_request:
     branches:
       - master
+  merge_group:
+    branches:
+      - master
 jobs:
   linux:
     name: Haskell-CI - Linux - ${{ matrix.compiler }}
@@ -32,6 +35,11 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20251128
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20251128
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
@@ -121,6 +129,21 @@ jobs:
           HCKIND: ${{ matrix.compilerKind }}
           HCNAME: ${{ matrix.compiler }}
           HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
       - name: Set PATH and environment variables
         run: |
           echo "$HOME/.cabal/bin" >> $GITHUB_PATH
@@ -131,7 +154,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -159,6 +182,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -182,7 +217,7 @@ jobs:
           chmod a+x $HOME/.cabal/bin/cabal-plan
           cabal-plan --version
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           path: source
       - name: initial cabal.project for sdist
@@ -214,6 +249,9 @@ jobs:
           if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(generic-data)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
diff --git a/generic-data.cabal b/generic-data.cabal
index 11ecaaa..f5415b2 100644
--- a/generic-data.cabal
+++ b/generic-data.cabal
@@ -18,7 +18,8 @@ cabal-version:       >=1.10
 tested-with:         GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4,
                      GHC == 8.6.5, GHC == 8.10.7, GHC == 9.0.2,
                      GHC == 9.2.8, GHC == 9.4.8, GHC == 9.6.7,
-                     GHC == 9.8.4, GHC == 9.10.2, GHC == 9.12.2
+                     GHC == 9.8.4, GHC == 9.10.2, GHC == 9.12.2,
+                     GHC == 9.14.1
 
 library
   hs-source-dirs:      src
@@ -46,7 +47,7 @@ library
     base-orphans >= 0.8.8,
     ghc-boot-th,
     show-combinators,
-    base >= 4.9 && < 4.22
+    base >= 4.9 && < 4.23
   if impl(ghc < 8.6)
     build-depends: contravariant
   hs-source-dirs:      orphans