diff --git a/config/cfgroot/useragents b/config/cfgroot/useragents
index a9663f398..9ddd6d82b 100644
--- a/config/cfgroot/useragents
+++ b/config/cfgroot/useragents
@@ -17,6 +17,7 @@ NETSCAPE,Netscape,(^Mozilla\/4.[7|8])|(Netscape)
 OPERA,Opera,(Opera)
 SAFARI,Safari,(Safari)
 SYMLU,Symantec LiveUpdate,(Symantec\sLiveUpdate)
+THUNDERBIRD,Thunderbird,(Thunderbird)
 WGA,WGA,(LegitCheck)
 WGET,Wget,(Wget)
 WINUPD,Windows Update,(Industry\sUpdate\sControl)|(Windows\sUpdate)|(Service\sPack\sSetup)|(Progressive\sDownload)|(Windows\-Update\-Agent)|(Microsoft\sBITS)