diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index b2597999513fe54e8cdca38482c30fd60232deab..081da851c83ee6255908f232970e5cb2931597c6 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -484,4 +484,5 @@ AVFilter avfilter_vf_scale = {
 
     .inputs    = avfilter_vf_scale_inputs,
     .outputs   = avfilter_vf_scale_outputs,
+    .priv_class = &scale_class,
 };