diff --git a/src/util.cpp b/src/util.cpp
index 6dc2f3b6da2..ccd39aa2296 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -22,6 +22,7 @@ namespace boost {
 #include <boost/interprocess/sync/interprocess_mutex.hpp>
 #include <boost/interprocess/sync/interprocess_recursive_mutex.hpp>
 #include <boost/foreach.hpp>
+#include <boost/thread.hpp>
 
 using namespace std;
 using namespace boost;
@@ -193,6 +194,8 @@ inline int OutputDebugStringF(const char* pszFormat, ...)
         if (fileout)
         {
             static bool fStartedNewLine = true;
+            static boost::mutex mutexDebugLog;
+            boost::mutex::scoped_lock scoped_lock(mutexDebugLog);
 
             // Debug print useful for profiling
             if (fLogTimestamps && fStartedNewLine)