diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index eceda8a9bc..2eaffa580c 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -171,9 +171,9 @@ static int alloc_scratch_buffers(H264SliceContext *sl, int linesize)
     // (= 21x21 for  h264)
     av_fast_malloc(&sl->edge_emu_buffer, &sl->edge_emu_buffer_allocated, alloc_size * 2 * 21);
 
-    av_fast_malloc(&sl->top_borders[0], &sl->top_borders_allocated[0],
+    av_fast_mallocz(&sl->top_borders[0], &sl->top_borders_allocated[0],
                    h->mb_width * 16 * 3 * sizeof(uint8_t) * 2);
-    av_fast_malloc(&sl->top_borders[1], &sl->top_borders_allocated[1],
+    av_fast_mallocz(&sl->top_borders[1], &sl->top_borders_allocated[1],
                    h->mb_width * 16 * 3 * sizeof(uint8_t) * 2);
 
     if (!sl->bipred_scratchpad || !sl->edge_emu_buffer ||