diff --git a/win/winvnc/VNCServerService.cxx b/win/winvnc/VNCServerService.cxx
index 1a2a8e9..481df21 100644
--- a/win/winvnc/VNCServerService.cxx
+++ b/win/winvnc/VNCServerService.cxx
@@ -97,9 +97,8 @@
     if (GetSessionUserTokenWin(&hToken))
     {
         ModuleFileName filename;
-        static const char cmdLineFmt[] = "\"%s\" -noconsole -service_run";
-        TCharArray cmdLine(_tcslen(filename.buf) + sizeof(cmdLineFmt)/sizeof(cmdLineFmt[0]));
-        _stprintf(cmdLine.buf, cmdLineFmt, filename.buf);
+        TCharArray cmdLine;
+        cmdLine.format("\"%s\" -noconsole -service_run", filename.buf);
         STARTUPINFO si;
         ZeroMemory(&si, sizeof si);
         si.cb = sizeof si;