diff --git a/debug.hpp b/debug.hpp
index ed393e38..b49c5141 100644
--- a/debug.hpp
+++ b/debug.hpp
@@ -21,6 +21,7 @@
 #include <algorithm>
 #include <stdexcept>
 #include <string>
+#include <thread>
 
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -59,7 +60,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 #define TRACE {                                                                     \
     DEBUG_ONLY (                                                                    \
-        std::cerr << __FILE__ << ":" << __func__ << ":" << __LINE__ << std::endl;   \
+        std::clog << "tid: " << std::this_thread::get_id () << "; " << __FILE__ << ":" << __func__ << ":" << __LINE__ << std::endl;   \
     );                                                                              \
 }