diff --git a/.github/workflows/codechecks.yml b/.github/workflows/codechecks.yml
index 0fc346dc0..954d0f570 100644
--- a/.github/workflows/codechecks.yml
+++ b/.github/workflows/codechecks.yml
@@ -8,10 +8,11 @@ jobs:
       - uses: actions/checkout@v3
       - name: Install dependencies
         run: |
-          sudo apt install clang-format
+          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+          sudo apt-get install clang-format-19
       - name: Run clang-format
         run: |
           mkdir Release
           cd Release
           cmake ..
-          make codecheck
\ No newline at end of file
+          make codecheck
diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index 025b981b8..1b87c90bf 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -18,7 +18,7 @@ jobs:
           doxyfile-path: 'docs/Doxyfile'
           enable-latex: true
       - name: Save documentation
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: documentation
           path: ./docs/build/html
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 12d787a86..8ba9752c1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,10 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-22.04, ubuntu-latest, macos-13, macos-latest]
+        version: [13] # GCC version
       fail-fast: false
+    env:
+      GCC_V: ${{ matrix.version }}
     steps:
       - uses: actions/checkout@v4
       - uses: conda-incubator/setup-miniconda@v3
@@ -17,12 +20,21 @@ jobs:
       - name: Install ubuntu dependencies
         if: startsWith(matrix.os, 'ubuntu')
         run: sudo apt update && sudo apt install build-essential cmake lcov
-      - name: Install svZeroDSolver
+      - name: Create conda environment
         run: |
           #export PATH="/usr/share/miniconda/bin:$PATH"
           #alias conda="$CONDA/bin/conda"
           conda create -n zerod python=3.11.4
-          conda run -n zerod pip install -e ".[dev]"
+      - name: Install dependencies to get correct version numbers (Ubuntu)
+        if: startsWith(matrix.os, 'ubuntu')
+        run: conda install -n zerod -c conda-forge libstdcxx-ng=${GCC_V} gcc=${GCC_V}
+      - name: Install dependencies to get correct version numbers (MacOS)
+        if: startsWith(matrix.os, 'macos')
+        run: |
+          brew install gcc@${GCC_V}
+          ln -s /usr/local/bin/gcc-${GCC_V} /usr/local/bin/gcc
+      - name: Install svZeroDSolver
+        run: conda run -n zerod pip install -e ".[dev]"
       - name: Install Networkx
         run: |
             conda run -n zerod pip install networkx
@@ -59,7 +71,7 @@ jobs:
           make coverage
       - name: Save coverage report
         if: startsWith(matrix.os, 'ubuntu-22.04')
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: coverage_report
           path: Release/coverage
@@ -74,7 +86,7 @@ jobs:
           cpack
           cp distribution/svZeroDSolver_* ..
       - name: Upload installer
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.os }} installer
           path: svZeroDSolver_*
diff --git a/src/solve/SimulationParameters.cpp b/src/solve/SimulationParameters.cpp
index a8a541332..b2a5e33ec 100644
--- a/src/solve/SimulationParameters.cpp
+++ b/src/solve/SimulationParameters.cpp
@@ -444,8 +444,8 @@ void create_external_coupling(
           (connected_type == "BloodVessel")) {
         connections.push_back({connected_block, coupling_name});
       }  // connected_type == "ClosedLoopRCR"
-    }    // coupling_loc
-  }      // for (size_t i = 0; i < coupling_configs.length(); i++)
+    }  // coupling_loc
+  }  // for (size_t i = 0; i < coupling_configs.length(); i++)
 }
 
 void create_junctions(