diff --git a/include/plog/Appenders/RollingFileAppender.h b/include/plog/Appenders/RollingFileAppender.h
index 3b66728..5d1a6ed 100644
--- a/include/plog/Appenders/RollingFileAppender.h
+++ b/include/plog/Appenders/RollingFileAppender.h
@@ -35,6 +35,8 @@ namespace plog
 
         virtual void write(const Record& record) PLOG_OVERRIDE
         {
+            const std::string& line = Converter::convert(Formatter::format(record));
+
             util::MutexLock lock(m_mutex);
 
             if (m_firstWrite)
@@ -47,7 +49,7 @@ namespace plog
                 rollLogFiles();
             }
 
-            size_t bytesWritten = m_file.write(Converter::convert(Formatter::format(record)));
+            size_t bytesWritten = m_file.write(line);
 
             if (static_cast<size_t>(-1) != bytesWritten)
             {