diff --git src/logging.cc src/logging.cc
--- src/logging.cc
+++ src/logging.cc
@@ -1135,7 +1135,8 @@ void LogFileObject::Write(bool force_flush,
                     << setw(2) << tm_time.tm_min
                     << setw(2) << tm_time.tm_sec
                     << '.'
-                    << GetMainThreadPid();
+                    << GetMainThreadPid()
+                    << ".log";
     const string& time_pid_string = time_pid_stream.str();
 
     if (base_filename_selected_) {