diff --git a/.github/workflows/gcc11-no-sanitize.yml b/.github/workflows/gcc11-no-sanitize.yml
deleted file mode 100644
index eda80f2..0000000
--- a/.github/workflows/gcc11-no-sanitize.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: gcc-11 -fno-sanitize=all
-
-on:
-  push:
-    branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
-  workflow_dispatch:
-
-jobs:
-  gcc11-no-sanitize:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        cxxflags: ['"-O3 -fno-sanitize=all -std=c++20 -DRA_DO_OPT_SMALLVECTOR=0"',
-                   '"-O3 -fno-sanitize=all -std=c++20 -DRA_DO_OPT_SMALLVECTOR=1"',
-                   '"-O3 -fno-sanitize=all -DRA_DO_CHECK=0 -DNDEBUG -std=c++20"',
-                   '"-O3 -fno-sanitize=all -std=c++2b"']
-    steps:
-    - uses: actions/checkout@v3
-    - name: update
-      run: |
-         sudo apt update
-         sudo apt install gcc-11 g++-11
-    - name: configure
-      run: CXXFLAGS=${{matrix.cxxflags}} cmake .
-      env:
-        CXX: g++-11
-        CC: gcc-11
-    - name: make
-      run: make
-    - name: make test
-      run: make test
diff --git a/.github/workflows/gcc11.yml b/.github/workflows/gcc11.yml
deleted file mode 100644
index 91bef8b..0000000
--- a/.github/workflows/gcc11.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: gcc-11
-
-on:
-  push:
-    branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
-  workflow_dispatch:
-
-jobs:
-  gcc11:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        cxxflags: ['"-O3 -std=c++20 -DRA_DO_OPT_SMALLVECTOR=0"',
-                   '"-O3 -std=c++20 -DRA_DO_OPT_SMALLVECTOR=1"',
-                   '"-O3 -DRA_DO_CHECK=0 -DNDEBUG -std=c++20"',
-                   '"-O3 -std=c++2b"']
-    steps:
-    - uses: actions/checkout@v3
-    - name: update
-      run: |
-         sudo apt update
-         sudo apt install gcc-11 g++-11
-    - name: configure
-      run: CXXFLAGS=${{matrix.cxxflags}} cmake .
-      env:
-        CXX: g++-11
-        CC: gcc-11
-    - name: make
-      run: make
-    - name: make test
-      run: make test
diff --git a/.github/workflows/gcc14-no-sanitize.yml b/.github/workflows/gcc14-no-sanitize.yml
index 66902ad..460cd10 100644
--- a/.github/workflows/gcc14-no-sanitize.yml
+++ b/.github/workflows/gcc14-no-sanitize.yml
@@ -12,10 +12,9 @@ jobs:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
-        cxxflags: ['"-O3 -fno-sanitize=all -std=c++20 -DRA_DO_OPT_SMALLVECTOR=0"',
-                   '"-O3 -fno-sanitize=all -std=c++20 -DRA_DO_OPT_SMALLVECTOR=1"',
-                   '"-O3 -fno-sanitize=all -DRA_DO_CHECK=0 -DNDEBUG -std=c++20"',
-                   '"-O3 -fno-sanitize=all -std=c++2b"']
+        cxxflags: ['"-O3 -fno-sanitize=all -std=c++23 -DRA_DO_OPT_SMALLVECTOR=0"',
+                   '"-O3 -fno-sanitize=all -std=c++23 -DRA_DO_OPT_SMALLVECTOR=1"',
+                   '"-O3 -fno-sanitize=all -DRA_DO_CHECK=0 -DNDEBUG -std=c++23"']
     steps:
     - uses: actions/checkout@v4
     - name: update
diff --git a/.github/workflows/gcc14.yml b/.github/workflows/gcc14.yml
index 38955ab..1a96a11 100644
--- a/.github/workflows/gcc14.yml
+++ b/.github/workflows/gcc14.yml
@@ -12,10 +12,9 @@ jobs:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
-        cxxflags: ['"-O3 -std=c++20 -DRA_DO_OPT_SMALLVECTOR=0"',
-                   '"-O3 -std=c++20 -DRA_DO_OPT_SMALLVECTOR=1"',
-                   '"-O3 -DRA_DO_CHECK=0 -DNDEBUG -std=c++20"',
-                   '"-O3 -std=c++2b"']
+        cxxflags: ['"-O3 -std=c++23 -DRA_DO_OPT_SMALLVECTOR=0"',
+                   '"-O3 -std=c++23 -DRA_DO_OPT_SMALLVECTOR=1"',
+                   '"-O3 -DRA_DO_CHECK=0 -DNDEBUG -std=c++23"']
     steps:
     - uses: actions/checkout@v4
     - name: update
diff --git a/README.md b/README.md
index b8951a9..586cd7a 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 
-[![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc11.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc11.yml) [![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc11-no-sanitize.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc11-no-sanitize.yml) [![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc14.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc14.yml) [![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc14-no-sanitize.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc14-no-sanitize.yml)
+[![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc14.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc14.yml) [![C/C++ CI](https://github.com/lloda/ra-ra/actions/workflows/gcc14-no-sanitize.yml/badge.svg)](https://github.com/lloda/ra-ra/actions/workflows/gcc14-no-sanitize.yml)
 
 # ra-ra