diff --git a/include/boost/thread/caller_context.hpp b/include/boost/thread/caller_context.hpp
index 1e341686..d035baf6 100644
--- a/include/boost/thread/caller_context.hpp
+++ b/include/boost/thread/caller_context.hpp
@@ -12,6 +12,7 @@
 #include <boost/thread/thread.hpp>
 #endif
 #include <boost/current_function.hpp>
+#include <boost/io/ios_state.hpp>
 #include <iomanip>
 
 #include <boost/config/abi_prefix.hpp>
@@ -43,9 +44,11 @@ namespace boost
 #endif
     {
       io::ios_flags_saver ifs(os);
-      os << ctx.filename << "["
+      os << std::setw(50) << ctx.filename << "["
          << std::setw(4) << std::right << std::dec<< ctx.lineno << "] ";
+#if defined BOOST_THREAD_USES_LOG_CURRENT_FUNCTION
       os << ctx.func << " " ;
+#endif
     }
     return os;
   }