diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index 275f45a3b5..5041d3a3d9 100644
--- a/libavcodec/pgssubdec.c
+++ b/libavcodec/pgssubdec.c
@@ -367,7 +367,7 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
 
     /* Allocate memory for colors */
     sub->rects[0]->nb_colors    = 256;
-    sub->rects[0]->pict.data[1] = av_malloc(sub->rects[0]->nb_colors * sizeof(uint32_t));
+    sub->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
 
     memcpy(sub->rects[0]->pict.data[1], ctx->clut, sub->rects[0]->nb_colors * sizeof(uint32_t));