diff --git a/.hgtags b/.hgtags
index 394ff8b2ce38..112f22810caa 100644
--- a/.hgtags
+++ b/.hgtags
@@ -308,3 +308,4 @@ a47fcf8f07f9c3e1b3f5fda7c49634809fed27cc FIREFOX_BETA_129_BASE
 c6bbeb21b9650e398bd364eba25a1e61bd285a19 FIREFOX_BETA_130_BASE
 a12975dc04594d4ebd1d3e2927c6c1f18b7aa09c FIREFOX_NIGHTLY_130_END
 c9a192c047cde29cd4369733df6c27c9326990e9 FIREFOX_BETA_131_BASE
+2764529cc7a6f24781273f93d7af9805e1f45876 FIREFOX_NIGHTLY_131_END