diff --git a/.hgtags b/.hgtags
index 3b7591b093e..5034687340b 100644
--- a/.hgtags
+++ b/.hgtags
@@ -119,3 +119,4 @@ b297a6727acfd21e757ddd38cd61894812666265 FIREFOX_AURORA_36_BASE
 1b6bf6612c0f4d4fee81d18bf18016e692f874e1 FIREFOX_AURORA_39_BASE
 66a95a483d2c77dfc387019336d18093acd6aac2 FIREFOX_AURORA_40_BASE
 312c68b16549de9cea1557f461d5d234bd5e0a7d FIREFOX_AURORA_41_BASE
+7a19194812eb767bee7cdf8fc36ba9a383c1bead FIREFOX_AURORA_42_BASE