diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index a376fbe0ca..33212a47c0 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -837,6 +837,7 @@ scale:
     out->height = outlink->h;
     out->color_range = outlink->color_range;
     out->colorspace = outlink->colorspace;
+    out->alpha_mode = outlink->alpha_mode;
     if (scale->out_chroma_loc != AVCHROMA_LOC_UNSPECIFIED)
         out->chroma_location = scale->out_chroma_loc;
     if (scale->out_primaries != -1)