diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 76e3614..02638d6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-# Copyright 2021-2025 Andrey Semashev
+# Copyright 2021-2026 Andrey Semashev
 #
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
@@ -71,12 +71,14 @@ jobs:
               - g++-10
           - toolset: gcc-11
             cxxstd: "11,14,17,20,23"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - g++-11
           - toolset: gcc-12
             cxxstd: "11,14,17,20,23"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - g++-12
           - toolset: gcc-13
@@ -91,18 +93,22 @@ jobs:
               - g++-14
           - toolset: gcc-15
             cxxstd: "11,14,17,20,23,26"
-            os: ubuntu-latest
-            container: ubuntu:25.04
+            os: ubuntu-26.04
             install:
               - g++-15
+          - toolset: gcc-16
+            cxxstd: "11,14,17,20,23,26"
+            os: ubuntu-26.04
+            install:
+              - g++-16
           - name: UBSAN
-            toolset: gcc-13
-            cxxstd: "11,14,17,20,23"
+            toolset: gcc-15
+            cxxstd: "11,14,17,20,23,26"
             ubsan: 1
             build_variant: debug
-            os: ubuntu-24.04
+            os: ubuntu-26.04
             install:
-              - g++-13
+              - g++-15
 
           # Linux, clang
           - toolset: clang
@@ -195,7 +201,8 @@ jobs:
           - toolset: clang
             compiler: clang++-11
             cxxstd: "11,14,17,20"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - clang-11
               - g++-11
@@ -203,7 +210,8 @@ jobs:
           - toolset: clang
             compiler: clang++-12
             cxxstd: "11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - clang-12
               - g++-11
@@ -211,7 +219,8 @@ jobs:
           - toolset: clang
             compiler: clang++-13
             cxxstd: "11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - clang-13
               - g++-11
@@ -219,7 +228,8 @@ jobs:
           - toolset: clang
             compiler: clang++-14
             cxxstd: "11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - clang-14
               - g++-11
@@ -227,7 +237,8 @@ jobs:
           - toolset: clang
             compiler: clang++-15
             cxxstd: "11,14,17,20,2b"
-            os: ubuntu-22.04
+            os: ubuntu-latest
+            container: ubuntu:22.04
             install:
               - clang-15
               - g++-11
@@ -264,41 +275,54 @@ jobs:
           - toolset: clang
             compiler: clang++-20
             cxxstd: "11,14,17,20,23,26"
-            os: ubuntu-latest
-            container: ubuntu:25.04
+            os: ubuntu-26.04
             install:
               - clang-20
           - toolset: clang
-            compiler: clang++-20
+            compiler: clang++-21
             cxxstd: "11,14,17,20,23,26"
-            os: ubuntu-latest
-            container: ubuntu:25.04
+            os: ubuntu-26.04
             install:
-              - clang-20
-              - libc++-20-dev
-              - libc++abi-20-dev
+              - clang-21
+          - toolset: clang
+            compiler: clang++-22
+            cxxstd: "11,14,17,20,23,26"
+            os: ubuntu-26.04
+            install:
+              - clang-22
+          - toolset: clang
+            compiler: clang++-22
+            cxxstd: "11,14,17,20,23,26"
+            os: ubuntu-26.04
+            install:
+              - clang-22
+              - libc++-22-dev
+              - libc++abi-22-dev
             cxxflags: -stdlib=libc++
             linkflags: -stdlib=libc++
           - name: UBSAN
             toolset: clang
-            compiler: clang++-18
+            compiler: clang++-22
             cxxstd: "11,14,17,20,23,26"
             cxxflags: -stdlib=libc++
             linkflags: "-stdlib=libc++ -lubsan"
             ubsan: 1
             build_variant: debug
-            os: ubuntu-24.04
+            os: ubuntu-26.04
             install:
-              - clang-18
-              - libc++-18-dev
-              - libc++abi-18-dev
+              - clang-22
+              - libc++-22-dev
+              - libc++abi-22-dev
 
           - toolset: clang
-            cxxstd: "11,14,17,20,2b"
             os: macos-14
+            cxxstd: "11,14,17,20,2b"
           - toolset: clang
-            cxxstd: "11,14,17,20,23"
             os: macos-15
+            cxxstd: "11,14,17,20,23,26"
+          - toolset: clang
+            os: macos-26
+            cxxstd: "11,14,17,20,23,26"
 
           - name: CMake tests
             cmake_tests: 1
@@ -434,6 +458,7 @@ jobs:
             BUILD_JOBS=$((nproc || sysctl -n hw.ncpu) 2> /dev/null)
             echo "BUILD_JOBS=$BUILD_JOBS" >> $GITHUB_ENV
             echo "CMAKE_BUILD_PARALLEL_LEVEL=$BUILD_JOBS" >> $GITHUB_ENV
+            echo BUILD_JOBS: $BUILD_JOBS
             DEPINST_ARGS=()
             GIT_VERSION="$(git --version | sed -e 's/git version //')"
             GIT_HAS_JOBS=1
@@ -485,25 +510,22 @@ jobs:
             git submodule update --init tools/boostdep
             DEPINST_ARGS+=("$LIBRARY")
             python tools/boostdep/depinst/depinst.py "${DEPINST_ARGS[@]}"
-            if [ -z "${{matrix.cmake_tests}}" ]
-            then
-                ./bootstrap.sh
-                ./b2 headers
-                if [ -n "${{matrix.compiler}}" -o -n "$GCC_TOOLCHAIN_ROOT" ]
-                then
-                    echo -n "using ${{matrix.toolset}} : : ${{matrix.compiler}}" > ~/user-config.jam
-                    if [ -n "$GCC_TOOLCHAIN_ROOT" ]
-                    then
-                        echo -n " : <compileflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\" <linkflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\"" >> ~/user-config.jam
-                    fi
-                    echo " ;" >> ~/user-config.jam
-                fi
-            fi
 
       - name: Run tests
         if: matrix.cmake_tests == ''
         run: |
             cd boost-root
+            ./bootstrap.sh
+            ./b2 headers
+            if [ -n "${{matrix.compiler}}" -o -n "$GCC_TOOLCHAIN_ROOT" ]
+            then
+                echo -n "using ${{matrix.toolset}} : : ${{matrix.compiler}}" > ~/user-config.jam
+                if [ -n "$GCC_TOOLCHAIN_ROOT" ]
+                then
+                    echo -n " : <compileflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\" <linkflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\"" >> ~/user-config.jam
+                fi
+                echo " ;" >> ~/user-config.jam
+            fi
             B2_ARGS=("-j" "$BUILD_JOBS" "toolset=${{matrix.toolset}}" "cxxstd=${{matrix.cxxstd}}")
             if [ -n "${{matrix.build_variant}}" ]
             then
@@ -518,7 +540,7 @@ jobs:
             if [ -n "${{matrix.ubsan}}" ]
             then
                 export UBSAN_OPTIONS="print_stacktrace=1"
-                B2_ARGS+=("cxxflags=-fsanitize=undefined -fno-sanitize-recover=undefined" "linkflags=-fsanitize=undefined -fuse-ld=gold" "define=UBSAN=1" "debug-symbols=on" "visibility=global")
+                B2_ARGS+=("cxxflags=-fsanitize=undefined -fno-sanitize-recover=undefined" "linkflags=-fsanitize=undefined" "define=UBSAN=1" "debug-symbols=on" "visibility=global")
             fi
             if [ -n "${{matrix.cxxflags}}" ]
             then
@@ -605,12 +627,12 @@ jobs:
             rmdir /s /q "..\snapshot"
             git submodule update --init tools/boostdep
             python tools/boostdep/depinst/depinst.py --git_args "--jobs %GIT_FETCH_JOBS%" %LIBRARY%
-            cmd /c bootstrap
-            b2 -d0 headers
 
       - name: Run tests
         run: |
             cd boost-root
+            cmd /c bootstrap
+            b2 -d0 headers
             if not "${{matrix.cxxstd}}" == "" set CXXSTD=cxxstd=${{matrix.cxxstd}}
             if not "${{matrix.addrmd}}" == "" set ADDRMD=address-model=${{matrix.addrmd}}
             if not "${{matrix.build_variant}}" == "" (set BUILD_VARIANT=variant=${{matrix.build_variant}}) else (set BUILD_VARIANT=variant=%DEFAULT_BUILD_VARIANT%)