diff --git a/openbsc/src/e1_config.c b/openbsc/src/e1_config.c
index 16fd0d9..62bacf2 100644
--- a/openbsc/src/e1_config.c
+++ b/openbsc/src/e1_config.c
@@ -219,7 +219,7 @@
 	sign_ts = &line->ts[1-1];
 	rsl_ts = &line->ts[2-1];
 	oml_link = e1inp_sign_link_create(sign_ts, E1INP_SIGN_OML,
-					  bts->c0, 0, 0xff);
+					  bts->c0, 0xff, 0);
 	rsl_link = e1inp_sign_link_create(rsl_ts, E1INP_SIGN_RSL,
 					  bts->c0, 0, 0);