diff --git a/include/grgsm/demapping/universal_ctrl_chans_demapper.h b/include/grgsm/demapping/universal_ctrl_chans_demapper.h
index 08814dd..07264d8 100644
--- a/include/grgsm/demapping/universal_ctrl_chans_demapper.h
+++ b/include/grgsm/demapping/universal_ctrl_chans_demapper.h
@@ -48,7 +48,7 @@
        * class. gsm::universal_ctrl_chans_demapper::make is the public interface for
        * creating new instances.
        */
-      static sptr make(const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types);
+      static sptr make(unsigned int timeslot_nr, const std::vector<int> &starts_fn_mod51, const std::vector<int> &channel_types);
     };
 
   } // namespace gsm