diff --git a/libavfilter/drawutils.c b/libavfilter/drawutils.c
index 9b24cf7ac7..954c075a5f 100644
--- a/libavfilter/drawutils.c
+++ b/libavfilter/drawutils.c
@@ -134,7 +134,7 @@ int ff_draw_init(FFDrawContext *draw, enum PixelFormat format, unsigned flags)
 
     if (!desc->name)
         return AVERROR(EINVAL);
-    if (desc->flags & ~(PIX_FMT_PLANAR | PIX_FMT_RGB))
+    if (desc->flags & ~(PIX_FMT_PLANAR | PIX_FMT_RGB | PIX_FMT_PSEUDOPAL))
         return AVERROR(ENOSYS);
     for (i = 0; i < desc->nb_components; i++) {
         c = &desc->comp[i];
diff --git a/libavfilter/vf_pad.c b/libavfilter/vf_pad.c
index 9fc4b39b16..2a3c17ea18 100644
--- a/libavfilter/vf_pad.c
+++ b/libavfilter/vf_pad.c
@@ -262,7 +262,7 @@ static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
     AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
     int plane;
 
-    for (plane = 0; plane < 4 && outpicref->data[plane]; plane++) {
+    for (plane = 0; plane < 4 && outpicref->data[plane] && pad->draw.pixelstep[plane]; plane++) {
         int hsub = pad->draw.hsub[plane];
         int vsub = pad->draw.vsub[plane];
 
diff --git a/libavutil/pixdesc.c b/libavutil/pixdesc.c
index 233b217643..8572719822 100644
--- a/libavutil/pixdesc.c
+++ b/libavutil/pixdesc.c
@@ -220,6 +220,7 @@ const AVPixFmtDescriptor av_pix_fmt_descriptors[PIX_FMT_NB] = {
         .comp = {
             { 0, 0, 1, 0, 7 },        /* Y */
         },
+        .flags = PIX_FMT_PSEUDOPAL,
     },
     [PIX_FMT_MONOWHITE] = {
         .name = "monow",