diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
index 8c1602b33e..63412aef87 100644
--- a/libavfilter/vf_v360.c
+++ b/libavfilter/vf_v360.c
@@ -4258,8 +4258,8 @@ static int v360_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
                 int16_t *u = r->u[p] + ((j - slice_start) * uv_linesize + i) * elements;
                 int16_t *v = r->v[p] + ((j - slice_start) * uv_linesize + i) * elements;
                 int16_t *ker = r->ker[p] + ((j - slice_start) * uv_linesize + i) * elements;
-                uint8_t *mask8 = p ? NULL : r->mask + ((j - slice_start) * s->pr_width[0] + i);
-                uint16_t *mask16 = p ? NULL : (uint16_t *)r->mask + ((j - slice_start) * s->pr_width[0] + i);
+                uint8_t  *mask8  = (p || !r->mask) ? NULL : r->mask + ((j - slice_start) * s->pr_width[0] + i);
+                uint16_t *mask16 = (p || !r->mask) ? NULL : (uint16_t *)r->mask + ((j - slice_start) * s->pr_width[0] + i);
                 int in_mask, out_mask;
 
                 if (s->out_transpose)