diff --git a/include/linux/mISDNdsp.h b/include/linux/mISDNdsp.h
index 2c483d4..41d1eeb 100644
--- a/include/linux/mISDNdsp.h
+++ b/include/linux/mISDNdsp.h
@@ -25,6 +25,7 @@
 struct dsp_features {
 	int	hfc_id; /* unique id to identify the chip (or -1) */
 	int	hfc_dtmf; /* set if HFCmulti card supports dtmf */
+	int	hfc_conf; /* set if HFCmulti card supports conferences */
 	int	hfc_loops; /* set if card supports tone loops */
 	int	hfc_echocanhw; /* set if card supports echocancelation*/
 	int	pcm_id; /* unique id to identify the pcm bus (or -1) */