diff --git a/libavutil/tx.c b/libavutil/tx.c
index da8ebddd9a..aeb0d9dada 100644
--- a/libavutil/tx.c
+++ b/libavutil/tx.c
@@ -620,7 +620,7 @@ av_cold int ff_tx_init_subtx(AVTXContext *s, enum AVTXType type,
         sctx->len        = len;
         sctx->inv        = inv;
         sctx->type       = type;
-        sctx->flags      = flags;
+        sctx->flags      = cd->flags | flags;
         sctx->cd_self    = cd;
 
         s->fn[s->nb_sub] = cd->function;