diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 022c704c..f7cdc09b 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: 0.19.20240512
+# version: 0.19.20240514
 #
-# REGENDATA ("0.19.20240512",["github","cabal.project"])
+# REGENDATA ("0.19.20240514",["github","cabal.project"])
 #
 name: Haskell-CI
 on:
@@ -121,7 +121,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          if [ $((HCNUMVER >= 91000)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
+          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
           echo "GHCJSARITH=0" >> "$GITHUB_ENV"
         env:
@@ -150,17 +150,6 @@ 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
-          EOF
-          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -228,10 +217,7 @@ jobs:
             location: https://github.com/goldfirere/th-desugar
             tag:      ae6c075edb50175a99b35f0bdcf475b695a5ee78
           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: $_ installed\n" unless /^(singletons|singletons-base|singletons-th)$/; }' >> cabal.project.local
+          $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(Cabal|Cabal-syntax|singletons|singletons-base|singletons-th)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
       - name: dump install plan
diff --git a/cabal.haskell-ci b/cabal.haskell-ci
index 29812895..b9e157b4 100644
--- a/cabal.haskell-ci
+++ b/cabal.haskell-ci
@@ -4,6 +4,5 @@ unconstrained:          False
 jobs-selection:         any
 -- Needed to avoid https://github.com/haskell/cabal/issues/5423
 haddock-components:     libs
--- Using `active-repositories: ..., head.hackage.ghc.haskell.org:override`
--- tends not to work well with singletons-base's custom Setup script.
-head-hackage-override:  False
+-- Needed to avoid https://github.com/haskell/cabal/issues/9917
+installed:              +all -Cabal -Cabal-syntax