diff --git a/.github/workflows/cpp.yml b/.github/workflows/cpp.yml
index b1a05a87..61304999 100644
--- a/.github/workflows/cpp.yml
+++ b/.github/workflows/cpp.yml
@@ -13,8 +13,8 @@ jobs:
       matrix:
         config:
           - {compiler-options: "-Wall -Wextra -std=c++20"}
-          - {compiler-options: "-Wall -Wextra -Wno-sign-compare -std=c++2b"}
-          - {compiler-options: "-fanalyzer -Wno-analyzer-null-dereference -std=c++2b"}
+          - {compiler-options: "-Wall -Wextra -Wno-sign-compare -std=c++23"}
+          - {compiler-options: "-fanalyzer -Wno-analyzer-null-dereference -std=c++23"}
     steps:
       - uses: actions/checkout@v2
       - name: install g++
@@ -33,20 +33,20 @@ jobs:
     - name: install clang
       run: |
         sudo apt-key adv --fetch-keys https://apt.llvm.org/llvm-snapshot.gpg.key
-        sudo add-apt-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-16 main"
-        sudo apt-get install clang-16
+        sudo add-apt-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-17 main"
+        sudo apt-get install clang-17
     - name: compile
       run: |
         cd cpp
-        find . -name '*.cpp' -print0 | xargs -n1 -0 clang++-16 -Wall -Wextra -std=c++2b
+        find . -name '*.cpp' -print0 | xargs -n1 -0 clang++-17 -Wall -Wextra -std=c++23
 
   build-macos-clang:
     runs-on: macos-latest
     strategy:
       matrix:
         config:
-          - {compiler-options: "-Wall -Wextra -std=c++2b -isystem"}
-          - {compiler-options: "-Wall -Wextra -Wno-sign-compare -std=c++2b -isystem"}
+          - {compiler-options: "-Wall -Wextra -std=c++23 -isystem"}
+          - {compiler-options: "-Wall -Wextra -Wno-sign-compare -std=c++23 -isystem"}
     steps:
       - uses: actions/checkout@v2
       - name: compile
diff --git a/.github/workflows/java.yml b/.github/workflows/java.yml
index e3ee4924..912d83c3 100644
--- a/.github/workflows/java.yml
+++ b/.github/workflows/java.yml
@@ -9,7 +9,7 @@ jobs:
       matrix:
         config:
           - {java-version: 1.8}
-          - {java-version: 20}
+          - {java-version: 21}
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK