diff --git a/share/zoneinfo/backward b/share/zoneinfo/backward
index 47aaa8a3e5b..a65991c2ddc 100644
--- a/share/zoneinfo/backward
+++ b/share/zoneinfo/backward
@@ -25,9 +25,7 @@ Link	Asia/Ashgabat		Asia/Ashkhabad
 Link	Asia/Chongqing		Asia/Chungking
 Link	Asia/Dhaka		Asia/Dacca
 Link	Asia/Kolkata		Asia/Calcutta
-Link	Asia/Kolkata		Asia/Calcutta
 Link	Asia/Macau		Asia/Macao
-Link	Asia/Ho_Chi_Minh	Asia/Saigon
 Link	Asia/Jerusalem		Asia/Tel_Aviv
 Link	Asia/Ho_Chi_Minh	Asia/Saigon
 Link	Asia/Thimphu		Asia/Thimbu