diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 735302e3..c0769036 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,7 +13,7 @@ jobs:
 
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: sudo apt-get install libopenblas-dev liblapack-dev
       - run: make DLONG=${{ matrix.long }} USE_LAPACK=${{ matrix.lapack }}
       - run: make test DLONG=${{ matrix.long }} USE_LAPACK=${{ matrix.lapack }}
@@ -22,7 +22,7 @@ jobs:
 
   #  runs-on: windows-latest
   #  steps:
-  #    - uses: actions/checkout@v3
+  #    - uses: actions/checkout@v4
   #    - run: choco install clapack
   #    - run: make
   #    - run: make test
@@ -37,7 +37,7 @@ jobs:
 
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: brew install openblas lapack
       - run: make DLONG=${{ matrix.long }} USE_LAPACK=${{ matrix.lapack }}
       - run: make test DLONG=${{ matrix.long }} USE_LAPACK=${{ matrix.lapack }}
diff --git a/.github/workflows/build_mkl.yml b/.github/workflows/build_mkl.yml
index 1fd9acfc..647078f4 100644
--- a/.github/workflows/build_mkl.yml
+++ b/.github/workflows/build_mkl.yml
@@ -31,7 +31,7 @@ jobs:
         # source /opt/intel/mkl/bin/mklvars.sh
 
     - name: checkout project code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Build SCS MKL and test
       run: |
diff --git a/.github/workflows/build_openmp.yml b/.github/workflows/build_openmp.yml
index a46a0ed4..94f3e97f 100644
--- a/.github/workflows/build_openmp.yml
+++ b/.github/workflows/build_openmp.yml
@@ -12,7 +12,7 @@ jobs:
 
     steps:
     - name: checkout project code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: install deps
       run: sudo apt-get install libopenblas-dev liblapack-dev
diff --git a/.github/workflows/buildpp.yml b/.github/workflows/buildpp.yml
index 3df30e59..1a020cb7 100644
--- a/.github/workflows/buildpp.yml
+++ b/.github/workflows/buildpp.yml
@@ -7,7 +7,7 @@ jobs:
   linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: |
           sudo apt-get install libopenblas-dev liblapack-dev
           export CC=g++
@@ -19,7 +19,7 @@ jobs:
 
   #  runs-on: windows-latest
   #  steps:
-  #    - uses: actions/checkout@v3
+  #    - uses: actions/checkout@v4
   #    - run: choco install clapack
   #    - run: make
   #    - run: make test
@@ -28,7 +28,7 @@ jobs:
   mac:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: |
           brew install openblas lapack
           export CC=clang++
diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index 911d2c09..9803f41a 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -7,7 +7,7 @@ jobs:
   linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: |
           sudo apt-get install libopenblas-dev liblapack-dev
           mkdir out
@@ -26,7 +26,7 @@ jobs:
   mac:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: |
           brew install openblas lapack
           mkdir out
diff --git a/.github/workflows/cmake_mkl.yml b/.github/workflows/cmake_mkl.yml
index 15742818..42f3fdcd 100644
--- a/.github/workflows/cmake_mkl.yml
+++ b/.github/workflows/cmake_mkl.yml
@@ -25,7 +25,7 @@ jobs:
         # source /opt/intel/mkl/bin/mklvars.sh
 
     - name: checkout project code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Build SCS MKL and test
       run: |
diff --git a/.github/workflows/cmake_openmp.yml b/.github/workflows/cmake_openmp.yml
index 44273755..95cd16e4 100644
--- a/.github/workflows/cmake_openmp.yml
+++ b/.github/workflows/cmake_openmp.yml
@@ -7,7 +7,7 @@ jobs:
   linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: |
           sudo apt-get install libopenblas-dev liblapack-dev
           mkdir out
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 9b4a1532..ef9d0d2b 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: 'recursive'
 
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index bb768dd3..a6a3a48e 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Install OS dependencies
         run: |
           sudo apt-get install doxygen
diff --git a/.github/workflows/gpu.yml b/.github/workflows/gpu.yml
index 64b5981e..96a4ad94 100644
--- a/.github/workflows/gpu.yml
+++ b/.github/workflows/gpu.yml
@@ -7,7 +7,7 @@ jobs:
   linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: Jimver/cuda-toolkit@v0.2.5
       - run: sudo apt-get install libopenblas-dev liblapack-dev
       - run: make gpu
diff --git a/.github/workflows/valgrind.yml b/.github/workflows/valgrind.yml
index 5969704f..537e017e 100644
--- a/.github/workflows/valgrind.yml
+++ b/.github/workflows/valgrind.yml
@@ -7,7 +7,7 @@ jobs:
   linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: sudo apt-get update
       - run: sudo apt-get install libopenblas-dev liblapack-dev valgrind
       - run: make