diff --git a/spa/plugins/audioconvert/channelmix.c b/spa/plugins/audioconvert/channelmix.c
index a838580ab..f85309ca2 100644
--- a/spa/plugins/audioconvert/channelmix.c
+++ b/spa/plugins/audioconvert/channelmix.c
@@ -329,9 +329,9 @@ static int setup_convert(struct impl *this,
 		dst_mask |= 1ULL << (p < 64 ? p : 0);
 	}
 
-	if (src_mask & 1 || src_chan == 1)
+	if (src_mask & 1)
 		src_mask = default_mask(src_chan);
-	if (dst_mask & 1 || dst_chan == 1)
+	if (dst_mask & 1)
 		dst_mask = default_mask(dst_chan);
 
 	spa_log_info(this->log, "%p: %s/%d@%d->%s/%d@%d %08"PRIx64":%08"PRIx64, this,