diff --git a/plugin.rb b/plugin.rb
index cb3d809..27d56e1 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -44,7 +44,12 @@ after_initialize do
           p.user_id IS NOT NULL
 SQL
 
-        UserAction.exec_sql(sql, solved: UserAction::SOLVED)
+        # TODO post discourse 2.1 remove
+        if defined? DB
+          DB.exec(sql, solved: UserAction::SOLVED)
+        else
+          UserAction.exec_sql(sql, solved: UserAction::SOLVED)
+        end
       end
       $redis.set("solved_already_upgraded", "true")
     end