diff --git a/.github/workflows/ci-buildmatrix-cpp17.yml b/.github/workflows/ci-buildmatrix-cpp17.yml
index 12233c65..d2dfc038 100644
--- a/.github/workflows/ci-buildmatrix-cpp17.yml
+++ b/.github/workflows/ci-buildmatrix-cpp17.yml
@@ -7,7 +7,57 @@ on:
   workflow_dispatch:
 
 jobs:
+  prepare:
+    name: Download and cache source files
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Cache VBF tarball
+        id: vbf-cache
+        uses: actions/cache@v5
+        with:
+          path: VBF.tar.gz
+          key: vbf-tarball-${{ hashFiles('.github/workflows/ci-buildmatrix-cpp17.yml') }}
+          restore-keys: |
+            vbf-tarball-
+
+      - name: Download VBF tarball
+        if: steps.vbf-cache.outputs.cache-hit != 'true'
+        run: |
+          curl -L --retry 3 --retry-delay 3 https://syncandshare.desy.de/index.php/s/${{ secrets.VBFcpp17 }}/download -o VBF.tar.gz
+
+      - name: Cache SOFA tarball
+        id: sofa-cache
+        uses: actions/cache@v5
+        with:
+          path: sofa.tar.gz
+          key: sofa-tarball-${{ hashFiles('.github/workflows/ci-buildmatrix-cpp17.yml') }}
+          restore-keys: |
+            sofa-tarball-
+
+      - name: Download SOFA tarball
+        if: steps.sofa-cache.outputs.cache-hit != 'true'
+        run: |
+          curl -L --retry 3 --retry-delay 3 https://syncandshare.desy.de/index.php/s/${{ secrets.SOFA20231011 }}/download -o sofa.tar.gz
+
+      - name: Upload VBF tarball artifact
+        uses: actions/upload-artifact@v7
+        with:
+          name: vbf-tarball
+          path: VBF.tar.gz
+          retention-days: 30
+
+      - name: Upload SOFA tarball artifact
+        uses: actions/upload-artifact@v7
+        with:
+          name: sofa-tarball
+          path: sofa.tar.gz
+          retention-days: 30
+
   build:
+    needs: prepare
     strategy:
       matrix:
         os: [ubuntu-latest]
@@ -15,6 +65,7 @@ jobs:
           - "rootproject/root:latest"
           - "rootproject/root:6.26.06-ubuntu22.04"
           - "rootproject/root:6.32.04-ubuntu24.04"
+          - "rootproject/root:6.38.00-ubuntu25.10"
     runs-on: ${{ matrix.os }}
     container: ${{ matrix.root }}
 
@@ -25,17 +76,30 @@ jobs:
         run: |
           apt-get update && apt-get install -y libopenblas-dev
 
-      - name: vbf
+      - name: Download VBF tarball
+        uses: actions/download-artifact@v8
+        with:
+          name: vbf-tarball
+          path: .
+
+      - name: Build and install VBF
         run: |
-          curl -L --retry 3 --retry-delay 3 https://syncandshare.desy.de/index.php/s/${{ secrets.VBFcpp17 }}/download -o VBF.tar.gz
-          mkdir VBF && tar -xzf VBF.tar.gz -C VBF --strip-components=1
+          mkdir -p VBF && tar -xzf VBF.tar.gz -C VBF --strip-components=1
           cd VBF && ./configure --prefix=$(echo $GITHUB_WORKSPACE)/VBF
           make
           make install
 
-      - name: sofa
+      - name: Download SOFA tarball
+        uses: actions/download-artifact@v8
+        with:
+          name: sofa-tarball
+          path: .
+
+      - name: Extract SOFA
         run: |
-          curl -L --retry 3 --retry-delay 3 https://syncandshare.desy.de/index.php/s/${{ secrets.SOFA20231011 }}/download -o sofa/sofa.tar.gz
+          export EVNDISPSYS=$(echo $GITHUB_WORKSPACE)
+          mkdir -p "${EVNDISPSYS}/sofa"
+          cp sofa.tar.gz "${EVNDISPSYS}/sofa/sofa.tar.gz"
           ./install_sofa.sh
 
       - name: eventdisplay
@@ -45,5 +109,5 @@ jobs:
           export VBFSYS=$(echo $GITHUB_WORKSPACE)/VBF
           export LD_LIBRARY_PATH="${EVNDISPSYS}/obj:${EVNDISPSYS}/lib:${LD_LIBRARY_PATH}"
           export LD_LIBRARY_PATH="${VBFSYS}/lib:${LD_LIBRARY_PATH}"
-          export SOFASYS=/sofa
+          export SOFASYS="${EVNDISPSYS}/sofa"
           make -j 4 VTS
diff --git a/dockerfiles/Dockerfile b/dockerfiles/Dockerfile
index c8ba052a..3f40d86d 100644
--- a/dockerfiles/Dockerfile
+++ b/dockerfiles/Dockerfile
@@ -1,4 +1,4 @@
-ARG ROOT_VERSION=6.32.04-ubuntu24.04
+ARG ROOT_VERSION=6.38.00-ubuntu25.10
 FROM rootproject/root:${ROOT_VERSION} AS build
 ARG VBF_VERSION=0.3.4
 ARG BUILD_BRANCH=main
diff --git a/docs/changes/358.maintenance.md b/docs/changes/358.maintenance.md
new file mode 100644
index 00000000..bbde6d5a
--- /dev/null
+++ b/docs/changes/358.maintenance.md
@@ -0,0 +1 @@
+Updates to allow for compilation with ROOT >=v6.38. Adjustment of CI.
diff --git a/src/CData.cpp b/src/CData.cpp
index 6a4a3b12..62a5a3cd 100644
--- a/src/CData.cpp
+++ b/src/CData.cpp
@@ -1094,6 +1094,7 @@ TTree* CData::getXGBTree( string file_name, string file_suffix, string tree_name
         cout << "(this might be ok if no XGB analysis results are requested)" << endl;
         return 0;
     }
+    cout << "CData: opened XGB file " << file_name << endl;
     fXGBFiles.push_back( iFile );
 
     TTree* iXGB_tree = ( TTree* )iFile->Get( tree_name.c_str() );
diff --git a/src/VPlotAnasumHistograms.cpp b/src/VPlotAnasumHistograms.cpp
index 39eb3a9b..f56f34b5 100644
--- a/src/VPlotAnasumHistograms.cpp
+++ b/src/VPlotAnasumHistograms.cpp
@@ -245,7 +245,7 @@ void VPlotAnasumHistograms::plot_mscPlots( int irebin, double xmin, double xmax,
 
         VDouble_gauss* fdouble_gauss = new VDouble_gauss();
 
-        TF1* hmscw_diff_fit = new TF1( hname, fdouble_gauss, -1.5, 1.5, 4, "VDouble_gauss" );
+        TF1* hmscw_diff_fit = new TF1( hname, fdouble_gauss, -1.5, 1.5, 4 );
         //TF1 *hmscw_diff_fit = new TF1( hname,double_gauss, -1.5, 1.5, 4);
         hmscw_diff_fit->SetParameter( 0, hmscw_diff->GetMaximum() );
         hmscw_diff_fit->SetParameter( 1, 0. );
@@ -286,7 +286,7 @@ void VPlotAnasumHistograms::plot_mscPlots( int irebin, double xmin, double xmax,
 
         hmscl_diff->Draw( "hist e " );
         sprintf( hname, "%s_fit", hmscl_diff->GetName() );
-        TF1* hmscl_diff_fit = new TF1( hname, fdouble_gauss, -1.5, 2.5, 4, "VDouble_gauss" );
+        TF1* hmscl_diff_fit = new TF1( hname, fdouble_gauss, -1.5, 2.5, 4 );
         hmscl_diff_fit->SetParameter( 0, hmscl_diff->GetMaximum() );
         hmscl_diff_fit->SetParameter( 1, 0. );
         hmscl_diff_fit->SetParameter( 2, 0.3 );
diff --git a/src/VStereoAnalysis.cpp b/src/VStereoAnalysis.cpp
index 3efe644b..fd35edca 100644
--- a/src/VStereoAnalysis.cpp
+++ b/src/VStereoAnalysis.cpp
@@ -1982,7 +1982,7 @@ CData* VStereoAnalysis::getDataFromFile( int i_runNumber )
             false,
             iFileName,
             ( fRunPara->fEnergyReconstructionMethod == 2 || fRunPara->fDirectionReconstructionMethod == 2 )
-                ? fRunPara->fXGB_stereo_file_suffix : "",
+            ? fRunPara->fXGB_stereo_file_suffix : "",
             ""  // GH XGB tree loaded later, after analysis type is known from cut file
         );
         // read current (major) epoch from data file
diff --git a/src/makeEffectiveArea.cpp b/src/makeEffectiveArea.cpp
index fbf790b3..63ec890b 100644
--- a/src/makeEffectiveArea.cpp
+++ b/src/makeEffectiveArea.cpp
@@ -181,7 +181,7 @@ int main( int argc, char* argv[] )
     }
 
     const bool i_need_stereo_xgb = ( fRunPara->fEnergyReconstructionMethod == 2
-                                        || fRunPara->fDirectionReconstructionMethod == 2 );
+                                     || fRunPara->fDirectionReconstructionMethod == 2 );
     CData d( c, true, false, fRunPara->fdatafile,
              i_need_stereo_xgb ? fRunPara->fXGB_stereo_file_suffix : "",
              fCuts->useXGBoostCuts() ? fRunPara->fXGB_gh_file_suffix : "" );
diff --git a/src/printRunParameter.cpp b/src/printRunParameter.cpp
index 1c5474df..b37d3501 100644
--- a/src/printRunParameter.cpp
+++ b/src/printRunParameter.cpp
@@ -103,7 +103,7 @@ bool readRunParameter( TFile* fIn, string iPara )
                                           iPara.find( "updated-runinfo" ) != string::npos ) << "\t";
         cout << fPar->getInstrumentEpoch( true ) << "\t";
         cout << fPar->getAtmosphereID( iPara.find( "updated-runinfo" ) != string::npos ) << "\t";
-        if (fPar->fDBRunType.size() > 0 ) cout << fPar->fDBRunType << "\t";
+        if( fPar->fDBRunType.size() > 0 ) cout << fPar->fDBRunType << "\t";
         else cout << "no_db_runtype \t";
         for( unsigned int i = 0; i < fPar->fTelToAnalyze.size(); i++ )
         {