diff --git a/libavfilter/vf_xfade.c b/libavfilter/vf_xfade.c
index f52da5570b..a0e2e61d40 100644
--- a/libavfilter/vf_xfade.c
+++ b/libavfilter/vf_xfade.c
@@ -1406,6 +1406,7 @@ static void fadegrays##name##_transition(AVFilterContext *ctx,
         for (int x = 0; x < width; x++) {                                            \
             int bg[2][4];                                                            \
             if (is_rgb) {                                                            \
+                bg[0][0] = bg[1][0] = 0;                                             \
                 for (int p = 0; p < s->nb_planes; p++) {                             \
                     const type *xf0 = (const type *)(a->data[p] +                    \
                                                      y * a->linesize[p]);            \