diff --git a/.hgtags b/.hgtags
index a7ad329d42d..87ea87757d6 100644
--- a/.hgtags
+++ b/.hgtags
@@ -263,3 +263,4 @@ efe7dbc6088691757404e0c8745f894e3ca9c022 jdk9-b09
 c5495e25c7258ab5f96a1ae14610887d76d2be63 jdk9-b18
 2dcf544eb7ed5ac6a3f7813a32e33acea7442405 jdk9-b19
 89731ae72a761afdf4262e8b9513f302f6563f89 jdk9-b20
+28dd0c7beb3cad9cf95f17b4b5ad87eb447a4084 jdk9-b21