diff --git a/db/migrate/20260319062845_add_index_to_users_lower_login_on_postgres_and_sqlite.rb b/db/migrate/20260319062845_add_index_to_users_lower_login_on_postgres_and_sqlite.rb
index 7c4fe70d6..bb1bd3c8d 100644
--- a/db/migrate/20260319062845_add_index_to_users_lower_login_on_postgres_and_sqlite.rb
+++ b/db/migrate/20260319062845_add_index_to_users_lower_login_on_postgres_and_sqlite.rb
@@ -1,13 +1,11 @@
 class AddIndexToUsersLowerLoginOnPostgresAndSqlite < ActiveRecord::Migration[8.1]
   def up
     if Redmine::Database.postgresql? || Redmine::Database.sqlite?
-      add_index :users, "(lower(login))", name: "index_users_on_lower_login"
+      add_index :users, "(lower(login))", name: "index_users_on_lower_login", if_not_exists: true
     end
   end
 
   def down
-    if index_exists?(:users, name: "index_users_on_lower_login")
-      remove_index :users, name: "index_users_on_lower_login"
-    end
+    remove_index :users, name: "index_users_on_lower_login", if_exists: true
   end
 end
diff --git a/db/migrate/20260319170822_add_index_to_users_login.rb b/db/migrate/20260319170822_add_index_to_users_login.rb
index 4c6968fdb..28da54eef 100644
--- a/db/migrate/20260319170822_add_index_to_users_login.rb
+++ b/db/migrate/20260319170822_add_index_to_users_login.rb
@@ -1,9 +1,9 @@
 class AddIndexToUsersLogin < ActiveRecord::Migration[8.1]
   def up
-    add_index :users, :login
+    add_index :users, :login, if_not_exists: true
   end
 
   def down
-    remove_index :users, :login
+    remove_index :users, :login, if_exists: true
   end
 end