diff --git a/conf/logback.xml b/conf/logback.xml
index 363faeecc8..c4dd3eb9d2 100644
--- a/conf/logback.xml
+++ b/conf/logback.xml
@@ -13,6 +13,9 @@
     </triggeringPolicy>
     <encoder>
       <pattern>%-5level [%thread] %date{ISO8601} %F:%L - %msg%n</pattern>
+      <!-- old-style log format
+      <pattern>%5level [%thread] %date{ISO8601} %F (line %L) %msg%n</pattern>
+      -->
     </encoder>
   </appender>
   
@@ -28,4 +31,4 @@
   </root>
   
   <logger name="org.apache.thrift.server.TNonblockingServer" level="ERROR"/>
-</configuration>
\ No newline at end of file
+</configuration>