diff --git a/lib/plsql/schema.rb b/lib/plsql/schema.rb
index f6a5bf3..1394977 100644
--- a/lib/plsql/schema.rb
+++ b/lib/plsql/schema.rb
@@ -100,7 +100,7 @@ def default_timezone
       else
         @default_timezone ||
           # Use ActiveRecord class default_timezone when ActiveRecord connection is used
-          (@connection && (ar_class = @connection.activerecord_class) && ar_class.default_timezone) ||
+          (@connection && @connection.time_zone == "UTC" ? :utc : nil) ||
           # default to local timezone
           :local
       end