diff --git a/include/Application.h b/include/Application.h
index 0408982a..ac061293 100644
--- a/include/Application.h
+++ b/include/Application.h
@@ -37,15 +37,17 @@ void ShowUsage();
 
 }  // namespace CommandLineOptions
 
+class G4VSteppingVerbose;
+
 class Application {
    public:
     void Run(const CommandLineOptions::Options& options);
 
-    ~Application() = default;
+    ~Application();
 
    private:
     SimulationManager fSimulationManager;
-
+    G4VSteppingVerbose* fSteppingVerbose;
     void ValidateOutputFile(const std::string& outputFile) const;
 };
 
diff --git a/src/Application.cxx b/src/Application.cxx
index 658b553a..b10fa026 100644
--- a/src/Application.cxx
+++ b/src/Application.cxx
@@ -380,7 +380,8 @@ void Application::Run(const CommandLineOptions::Options& options) {
     long seed = metadata->GetSeed();
     CLHEP::HepRandom::setTheSeed(seed);
 
-    G4VSteppingVerbose::SetInstance(new SteppingVerbose(&fSimulationManager));
+    fSteppingVerbose = new SteppingVerbose(&fSimulationManager);
+    G4VSteppingVerbose::SetInstance(fSteppingVerbose);
 
 #ifndef GEANT4_WITHOUT_G4RunManagerFactory
     auto runManagerType = G4RunManagerType::Default;
@@ -544,3 +545,5 @@ void Application::ValidateOutputFile(const string& filename) const {
         exit(1);
     }
 }
+
+Application::~Application() = default;
diff --git a/test/src/examples.cxx b/test/src/examples.cxx
index fa11e7c7..e2817ffc 100644
--- a/test/src/examples.cxx
+++ b/test/src/examples.cxx
@@ -167,6 +167,83 @@ TEST(restG4, Example_04_Muons) {
     cout << "Number of entries: " << run.GetEntries() << endl;
 }
 
+TEST(restG4, MergeFiles) {
+    // cd into example
+    const auto originalPath = fs::current_path();
+    const auto thisExamplePath = examplesPath / "04.MuonScan";
+    fs::current_path(thisExamplePath);
+
+    CommandLineOptions::Options options;
+    options.rmlFile = "CosmicMuonsFromWall.rml";
+
+    // create "merge" directory
+    auto mergeDirectory = thisExamplePath / "merge";
+    fs::create_directory(mergeDirectory);
+    options.nEvents = 1000;
+
+    options.outputFile = mergeDirectory / "muons1.root";
+    {
+        string command =
+            "restG4 CosmicMuonsFromWall.rml -n " + to_string(options.nEvents) + " -o " + options.outputFile;
+        const auto result = system(command.c_str());
+        EXPECT_EQ(result, 0);
+    }
+
+    options.nEvents = 500;
+    options.outputFile = mergeDirectory / "muons2.root";
+    {
+        string command =
+            "restG4 CosmicMuonsFromWall.rml -n " + to_string(options.nEvents) + " -o " + options.outputFile;
+        const auto result = system(command.c_str());
+        EXPECT_EQ(result, 0);
+    }
+
+    options.nEvents = 200;
+    options.outputFile = mergeDirectory / "muons3.root";
+    {
+        string command =
+            "restG4 CosmicMuonsFromWall.rml -n " + to_string(options.nEvents) + " -o " + options.outputFile;
+        const auto result = system(command.c_str());
+        EXPECT_EQ(result, 0);
+    }
+
+    int nEntries = 0;
+    {
+        TRestRun run(mergeDirectory / "muons1.root");
+        nEntries += run.GetEntries();
+    }
+    {
+        TRestRun run(mergeDirectory / "muons2.root");
+        nEntries += run.GetEntries();
+    }
+    {
+        TRestRun run(mergeDirectory / "muons3.root");
+        nEntries += run.GetEntries();
+    }
+
+    cout << "Computed number of entries: " << nEntries << endl;
+
+    // run system command to merge files
+    const auto command =
+        "root -b -q \"$REST_PATH/macros/geant4/REST_Geant4_MergeRestG4Files.C(\\\"merge.root\\\", \\\"" +
+        mergeDirectory.string() + "\\\")\"";
+    cout << "Running command: " << command << endl;
+    const auto result = system(command.c_str());
+    EXPECT_EQ(result, 0);
+
+    TRestRun run("merge.root");
+    TRestGeant4Metadata* metadata = (TRestGeant4Metadata*)run.GetMetadataClass("TRestGeant4Metadata");
+    if (metadata == nullptr) {
+        cerr << "TRestGeant4Metadata not found!" << endl;
+        exit(1);
+    }
+    cout << "Number of entries: " << run.GetEntries() << endl;
+    cout << "Number of primaries: " << metadata->GetNumberOfEvents() << endl;
+
+    EXPECT_EQ(metadata->GetNumberOfEvents(), 1700);
+    EXPECT_EQ(run.GetEntries(), nEntries);
+}
+
 TEST(restG4, Example_04_Muons_MT) {
     // cd into example
     const auto originalPath = fs::current_path();