diff --git a/.hgtags b/.hgtags
index 3a1d29035e..3eed1decf9 100644
--- a/.hgtags
+++ b/.hgtags
@@ -12,3 +12,4 @@ f688494c52bc7de9316ae436d20441371a73b3ec 2.8.0
 154ea5fb86b75faffd363439f1d6e990d6936c68 3.4.0
 af2746cd736ea6c0d5deee681e9e6286513d2837 3.6.0
 cdc30282449ca7b4991228fde5f99d38673a4fd0 3.8.0
+2b15dc5cabb1156e41e49bcc64b55ae085f2e325 4.0.0