diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 826f7f8..bb5188c 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -8,9 +8,9 @@
 #
 # For more information, see https://github.com/andreasabel/haskell-ci
 #
-# version: 0.17.20230928
+# version: 0.17.20231012
 #
-# REGENDATA ("0.17.20230928",["github","resolv.cabal"])
+# REGENDATA ("0.17.20231012",["github","resolv.cabal"])
 #
 name: Haskell-CI
 on:
@@ -32,11 +32,11 @@ jobs:
     strategy:
       matrix:
         include:
-          - compiler: ghc-9.8.0.20230919
+          - compiler: ghc-9.8.1
             compilerKind: ghc
-            compilerVersion: 9.8.0.20230919
+            compilerVersion: 9.8.1
             setup-method: ghcup
-            allow-failure: true
+            allow-failure: false
           - compiler: ghc-9.6.3
             compilerKind: ghc
             compilerVersion: 9.6.3
@@ -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 [ $((HCNUMVER >= 90800)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$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:
@@ -150,18 +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
-          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
@@ -215,11 +203,8 @@ jobs:
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "package resolv" >> cabal.project ; fi
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods" >> cabal.project ; fi
           cat >> cabal.project <<EOF
-          allow-newer: bytestring
+          allow-newer: containers
           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: $_ installed\n" unless /^(binary|resolv)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
@@ -260,13 +245,13 @@ jobs:
       - name: prepare for constraint sets
         run: |
           rm -f cabal.project.local
-      - name: constraint set latest-core-libs-Sep-2023
+      - name: constraint set containers-0.7
         run: |
-          if [ $((HCNUMVER >= 80200 && HCNUMVER < 90800)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='bytestring >= 0.12' --constraint='containers >= 0.7' all --dry-run ; fi
-          if [ $((HCNUMVER >= 80200 && HCNUMVER < 90800)) -ne 0 ] ; then cabal-plan topo | sort ; fi
-          if [ $((HCNUMVER >= 80200 && HCNUMVER < 90800)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='bytestring >= 0.12' --constraint='containers >= 0.7' --dependencies-only -j2 all ; fi
-          if [ $((HCNUMVER >= 80200 && HCNUMVER < 90800)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='bytestring >= 0.12' --constraint='containers >= 0.7' all ; fi
-          if [ $((HCNUMVER >= 80200 && HCNUMVER < 90800)) -ne 0 ] ; then $CABAL v2-test $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='bytestring >= 0.12' --constraint='containers >= 0.7' all ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='containers >= 0.7' all --dry-run ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then cabal-plan topo | sort ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='containers >= 0.7' --dependencies-only -j2 all ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then $CABAL v2-build $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='containers >= 0.7' all ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then $CABAL v2-test $ARG_COMPILER --enable-tests --disable-benchmarks --constraint='containers >= 0.7' all ; fi
       - name: save cache
         uses: actions/cache/save@v3
         if: always()
diff --git a/cabal.haskell-ci b/cabal.haskell-ci
index e8ba8c3..2f8fc2b 100644
--- a/cabal.haskell-ci
+++ b/cabal.haskell-ci
@@ -9,12 +9,11 @@ ghcup-jobs: True
 installed: +all -binary
 
 -- Test core libraries in versions newer than shipped with GHC
-constraint-set latest-core-libs-Sep-2023
-  constraints: bytestring >= 0.12
+constraint-set containers-0.7
   constraints: containers >= 0.7
-  ghc: >= 8.2 && < 9.7
+  ghc: >= 8.2
   tests: True
   run-tests: True
 
 raw-project
-  allow-newer: bytestring
+  allow-newer: containers
diff --git a/resolv.cabal b/resolv.cabal
index a1a3718..c180dba 100644
--- a/resolv.cabal
+++ b/resolv.cabal
@@ -56,7 +56,7 @@ extra-tmp-files:     autom4te.cache
                      cbits/hs_resolv_config.h
 
 tested-with:
-  GHC == 9.8.0
+  GHC == 9.8.1
   GHC == 9.6.3
   GHC == 9.4.7
   GHC == 9.2.8