diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9e3cd7c..63466ba 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -42,16 +42,16 @@ jobs:
       matrix:
         include:
           # Linux, gcc
-          - { compiler: gcc-12, cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-24.04 }
-          - { compiler: gcc-14, cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-24.04 }
-          - { compiler: gcc-14, cxxstd: '14,17,20', boostBranch: master, os: ubuntu-24.04 }
+          - { compiler: gcc-7, cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-22.04, container: 'ubuntu:20.04' }
+          - { compiler: gcc-14, cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-22.04 }
+          - { compiler: gcc-14, cxxstd: '14,17,20', boostBranch: master, os: ubuntu-22.04 }
 
           # Linux, clang
-          - { compiler: clang-14,  cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-24.04 }
-          - { compiler: clang-18,  cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-24.04 }
-          - { compiler: clang-18,  cxxstd: '14,17,20', boostBranch: master, os: ubuntu-24.04 }
+          - { compiler: clang-14,  cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-22.04 }
+          - { compiler: clang-18,  cxxstd: '14,17,20', boostBranch: boost-1.86.0, os: ubuntu-22.04 }
+          - { compiler: clang-18,  cxxstd: '14,17,20', boostBranch: master, os: ubuntu-22.04 }
 
-          - { name: Collect coverage, coverage: yes, compiler: gcc-14, cxxstd: '14', boostBranch: boost-1.86.0, os: ubuntu-24.04 }
+          - { name: Collect coverage, coverage: yes, compiler: gcc-8, cxxstd: '14', boostBranch: boost-1.86.0, os: ubuntu-22.04 }
 
     timeout-minutes: 120
     runs-on: ${{matrix.os}}
@@ -138,7 +138,7 @@ jobs:
         if: matrix.coverage
         run: |
           lcov --version
-          lcov --gcov-tool=gcov-14 --directory "$GITHUB_WORKSPACE/test" --capture --output-file all.info
+          lcov --gcov-tool=gcov-8 --directory "$GITHUB_WORKSPACE/test" --capture --output-file all.info
           # dump a summary on the console
           lcov --list all.info
           # Limit to our files (header-only in this case)