diff --git a/src/filters.c b/src/filters.c
index 1bd50c3..26bed64 100644
--- a/src/filters.c
+++ b/src/filters.c
@@ -1089,7 +1089,7 @@
 		goto end;
 
 	/* Consume data that all filters consider as forwarded. */
-	b_adv(chn->buf, ret);
+	c_adv(chn, ret);
 
 	/* Stop waiting data if the input in closed and no data is pending or if
 	 * the output is closed. */