diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1c1123e..d6898f0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,11 +47,11 @@ jobs:
             cxxstd: "03,11,14,17,2a"
             os: ubuntu-18.04
           - toolset: gcc-10
-            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-20.04
           - toolset: gcc-11
-            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-20.04
             install: g++-11
           - toolset: clang
             compiler: clang++-3.5
@@ -101,7 +101,7 @@ jobs:
           - toolset: clang
             compiler: clang++-8
             cxxstd: "03,11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-18.04
             install: clang-8
           - toolset: clang
             compiler: clang++-9
@@ -110,15 +110,15 @@ jobs:
             install: clang-9
           - toolset: clang
             compiler: clang++-10
-            cxxstd: "03,11,14,17,2a"
+            cxxstd: "03,11,14,17,20"
             os: ubuntu-20.04
           - toolset: clang
             compiler: clang++-11
-            cxxstd: "03,11,14,17,2a"
+            cxxstd: "03,11,14,17,20"
             os: ubuntu-20.04
           - toolset: clang
             compiler: clang++-12
-            cxxstd: "03,11,14,17,2a"
+            cxxstd: "03,11,14,17,20"
             os: ubuntu-20.04
           - toolset: clang
             cxxstd: "03,11,14,17,2a"