diff --git a/.github/workflows/ci-conan.yml b/.github/workflows/ci-conan.yml
index 09026c16..85a49cb7 100644
--- a/.github/workflows/ci-conan.yml
+++ b/.github/workflows/ci-conan.yml
@@ -89,7 +89,7 @@ jobs:
             }
           - {
               name: "Ubuntu Clang-12 + libstdc++11",
-              os: ubuntu-22.04,
+              os: ubuntu-20.04,
               compiler:
                 {
                   type: CLANG,
@@ -102,7 +102,7 @@ jobs:
             }
           - {
               name: "Ubuntu Clang-12 + libc++",
-              os: ubuntu-22.04,
+              os: ubuntu-20.04,
               compiler:
                 {
                   type: CLANG,
diff --git a/.github/workflows/ci-test-package-cmake.yml b/.github/workflows/ci-test-package-cmake.yml
index 37e4a5fd..d0692b62 100644
--- a/.github/workflows/ci-test-package-cmake.yml
+++ b/.github/workflows/ci-test-package-cmake.yml
@@ -93,7 +93,7 @@ jobs:
             }
           - {
               name: "Ubuntu Clang-12 + libstdc++11",
-              os: ubuntu-22.04,
+              os: ubuntu-20.04,
               compiler:
                 {
                   type: CLANG,
@@ -106,7 +106,7 @@ jobs:
             }
           - {
               name: "Ubuntu Clang-12 + libc++",
-              os: ubuntu-22.04,
+              os: ubuntu-20.04,
               compiler:
                 {
                   type: CLANG,