diff --git a/include/osmocom/abis/e1_input.h b/include/osmocom/abis/e1_input.h
index 3fbce5b..79455e1 100644
--- a/include/osmocom/abis/e1_input.h
+++ b/include/osmocom/abis/e1_input.h
@@ -173,6 +173,7 @@
 
 	struct e1inp_sign_link *	(*sign_link_up)(void *unit_info, struct e1inp_line *line, enum e1inp_sign_type type);
 	void	(*sign_link_down)(struct e1inp_line *line);
+	/* Called when a new message arrives. -EBADF must be returned if the osmo_fd in link (msg->dst) is destroyed. */
 	int	(*sign_link)(struct msgb *msg);
 };
 
diff --git a/src/input/ipaccess.c b/src/input/ipaccess.c
index 24a79ea..566fd64 100644
--- a/src/input/ipaccess.c
+++ b/src/input/ipaccess.c
@@ -279,7 +279,7 @@
 		     " sign_link returned error: %s.\n", strerror(-rc));
 	}
 
-	return 0;
+	return rc;
 err_msg:
 	msgb_free(msg);
 err:
@@ -790,8 +790,7 @@
 			"no action set for signalling messages.\n");
 		goto err;
 	}
-	link->line->ops->sign_link(msg);
-	return 0;
+	return link->line->ops->sign_link(msg);
 
 err:
 	ipa_client_conn_close(link);