diff --git a/backend/src/controllers/MergeController.cc b/backend/src/controllers/MergeController.cc
index 00574c0..ad7aa55 100644
--- a/backend/src/controllers/MergeController.cc
+++ b/backend/src/controllers/MergeController.cc
@@ -79,8 +79,9 @@ void MergeController::merge(
     Json::Value conflictsArray(Json::arrayValue);
     for (const auto &conflict : result.conflicts) {
         Json::Value conflictObj;
-        conflictObj["start_line"] = Json::Value::UInt64(conflict.start_line);
-        conflictObj["end_line"] = Json::Value::UInt64(conflict.end_line);
+        // Note: start_line and end_line are size_t (always non-negative)
+        conflictObj["start_line"] = static_cast<Json::UInt64>(conflict.start_line);
+        conflictObj["end_line"] = static_cast<Json::UInt64>(conflict.end_line);
         
         Json::Value baseLines(Json::arrayValue);
         for (const auto &line : conflict.base_lines) {
diff --git a/backend/src/main.cpp b/backend/src/main.cpp
index 0e4697a..3652ed9 100644
--- a/backend/src/main.cpp
+++ b/backend/src/main.cpp
@@ -24,8 +24,19 @@ int main(int argc, char* argv[]) {
         // Load configuration and start server
         app().loadConfigFile(config_file);
         
-        std::cout << "Server will listen on port " 
-                  << app().getListeners()[0].toPort << "\n";
+        // Display listener information if available
+        auto listeners = app().getListeners();
+        if (!listeners.empty()) {
+            try {
+                std::cout << "Server will listen on port " 
+                          << listeners[0].toPort << "\n";
+            } catch (...) {
+                std::cout << "Server listener configured\n";
+            }
+        } else {
+            std::cout << "Server configuration loaded\n";
+        }
+        
         std::cout << "Available endpoints:\n";
         std::cout << "  POST /api/merge - Three-way merge API\n";
         std::cout << "\nPress Ctrl+C to stop the server.\n\n";