diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
index 5ea6e0d865..299dbe9ff5 100644
--- a/libavfilter/vf_v360.c
+++ b/libavfilter/vf_v360.c
@@ -286,6 +286,8 @@ static int remap##ws##_##bits##bit_slice(AVFilterContext *ctx, void *arg, int jo
     const AVFrame *in = td->in;                                                                            \
     AVFrame *out = td->out;                                                                                \
                                                                                                            \
+    av_assert1(s->nb_planes <= AV_VIDEO_MAX_PLANES);                                                       \
+                                                                                                           \
     for (int stereo = 0; stereo < 1 + s->out_stereo > STEREO_2D; stereo++) {                               \
         for (int plane = 0; plane < s->nb_planes; plane++) {                                               \
             const unsigned map = s->map[plane];                                                            \