diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 5eaeb9d2..b9f0727a 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: 0.19.20241202
+# version: 0.19.20241219
 #
-# REGENDATA ("0.19.20241202",["github","cabal.project"])
+# REGENDATA ("0.19.20241219",["github","cabal.project"])
 #
 name: Haskell-CI
 on:
@@ -28,10 +28,10 @@ jobs:
     strategy:
       matrix:
         include:
-          - compiler: ghc-9.12.0.20241128
+          - compiler: ghc-9.12.1
             compilerKind: ghc
-            compilerVersion: 9.12.0.20241128
-            setup-method: ghcup-prerelease
+            compilerVersion: 9.12.1
+            setup-method: ghcup
             allow-failure: false
           - compiler: ghc-9.10.1
             compilerKind: ghc
@@ -104,10 +104,11 @@ jobs:
           mkdir -p "$HOME/.ghcup/bin"
           curl -sL https://downloads.haskell.org/ghcup/0.1.30.0/x86_64-linux-ghcup-0.1.30.0 > "$HOME/.ghcup/bin/ghcup"
           chmod a+x "$HOME/.ghcup/bin/ghcup"
-      - name: Install cabal-install
+      - name: Install cabal-install (prerelease)
         run: |
-          "$HOME/.ghcup/bin/ghcup" install cabal 3.12.1.0 || (cat "$HOME"/.ghcup/logs/*.* && false)
-          echo "CABAL=$HOME/.ghcup/bin/cabal-3.12.1.0 -vnormal+nowrap" >> "$GITHUB_ENV"
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prereleases-0.0.8.yaml;
+          "$HOME/.ghcup/bin/ghcup" install cabal 3.15.0.0.2024.10.3 || (cat "$HOME"/.ghcup/logs/*.* && false)
+          echo "CABAL=$HOME/.ghcup/bin/cabal-3.15.0.0.2024.10.3 -vnormal+nowrap" >> "$GITHUB_ENV"
       - name: Install GHC (GHCup)
         if: matrix.setup-method == 'ghcup'
         run: |
@@ -122,21 +123,6 @@ 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 https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prereleases-0.0.8.yaml;
-          "$HOME/.ghcup/bin/ghcup" install ghc "$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
@@ -184,7 +170,7 @@ jobs:
                         26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
                         f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
              key-threshold: 3
-          active-repositories: hackage.haskell.org
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
           EOF
           fi
           cat >> $CABAL_CONFIG <<EOF
@@ -255,13 +241,15 @@ jobs:
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-base-code-generator" >> cabal.project ; fi
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods" >> cabal.project ; fi
           cat >> cabal.project <<EOF
+          allow-newer: indexed-traversable:base
+
           source-repository-package
             type:     git
             location: https://github.com/goldfirere/th-desugar
             tag:      44158f7bb7faa2022795446505217b5e52862da5
           EOF
           if $HEADHACKAGE; then
-          echo "$($HCPKG list --simple-output | xargs -d' ' -n 1 | grep -v "^Cabal" | sed -E 's/([a-zA-Z-]+)-[0-9.]+/allow\-newer\: *:\1/g')" >> cabal.project
+          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 /^(Cabal|Cabal-syntax|singletons|singletons-base|singletons-base-code-generator|singletons-th)$/; }' >> cabal.project.local
           cat cabal.project
diff --git a/cabal.haskell-ci b/cabal.haskell-ci
index 23161777..b9e157b4 100644
--- a/cabal.haskell-ci
+++ b/cabal.haskell-ci
@@ -6,6 +6,3 @@ jobs-selection:         any
 haddock-components:     libs
 -- Needed to avoid https://github.com/haskell/cabal/issues/9917
 installed:              +all -Cabal -Cabal-syntax
--- Needed to work around https://github.com/haskell/cabal/issues/6522 and
--- https://github.com/haskell/cabal/issues/10500
-github-patches:         github.yml.patch
diff --git a/cabal.project b/cabal.project
index b7a66ea7..10df3480 100644
--- a/cabal.project
+++ b/cabal.project
@@ -7,3 +7,9 @@ source-repository-package
   type: git
   location: https://github.com/goldfirere/th-desugar
   tag: 44158f7bb7faa2022795446505217b5e52862da5
+
+-- TODO: Remove this after a fix for
+-- https://github.com/haskellari/indexed-traversable/issues/44 makes it to
+-- Hackage
+allow-newer:
+  indexed-traversable:base
diff --git a/github.yml.patch b/github.yml.patch
deleted file mode 100644
index 38a9a6bc..00000000
--- a/github.yml.patch
+++ /dev/null
@@ -1,22 +0,0 @@
-diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
-index 55fb206..c9db909 100644
---- a/.github/workflows/haskell-ci.yml
-+++ b/.github/workflows/haskell-ci.yml
-@@ -184,7 +184,7 @@ jobs:
-                         26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
-                         f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
-              key-threshold: 3
--          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
-+          active-repositories: hackage.haskell.org
-           EOF
-           fi
-           cat >> $CABAL_CONFIG <<EOF
-@@ -261,7 +261,7 @@ jobs:
-             tag:      730a0ed799c91324d42b70d3780d6b3215cafc3c
-           EOF
-           if $HEADHACKAGE; then
--          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
-+          echo "$($HCPKG list --simple-output | xargs -d' ' -n 1 | grep -v "^Cabal" | sed -E 's/([a-zA-Z-]+)-[0-9.]+/allow\-newer\: *:\1/g')" >> cabal.project
-           fi
-           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(Cabal|Cabal-syntax|singletons|singletons-base|singletons-base-code-generator|singletons-th)$/; }' >> cabal.project.local
-           cat cabal.project