diff --git a/intercept/src/chrometracer.h b/intercept/src/chrometracer.h
index 9e2db023..4c060381 100644
--- a/intercept/src/chrometracer.h
+++ b/intercept/src/chrometracer.h
@@ -366,9 +366,9 @@ class CChromeTracer
 
     std::ostream& flush()
     {
+        std::lock_guard<std::mutex> lock(m_Mutex);
         if( m_RecordBuffer.size() > 0 )
         {
-            std::lock_guard<std::mutex> lock(m_Mutex);
             flushRecords();
         }
         return m_TraceFile.flush();