diff --git a/.hgtags b/.hgtags
index a3ac6d30177e..0334972bcb78 100644
--- a/.hgtags
+++ b/.hgtags
@@ -5100,3 +5100,4 @@ f3783ad20bf40a11fb4b7ed088236c1a9f7be362 FIREFOX_128_7_0esr_RELEASE
 c685d5844a0e4f99ac535b6ffc641fbd07696c68 FIREFOX_128_8_0esr_BUILD1
 c685d5844a0e4f99ac535b6ffc641fbd07696c68 FIREFOX_128_8_0esr_RELEASE
 76f59a9f2161a539a9b6b000fcb7205e8d007b11 FIREFOX_128_9_0esr_BUILD1
+d156a4452c9d41aa78724265e41c26b7ff76941a FIREFOX_128_8_1esr_BUILD2