diff --git a/libswscale/slice.c b/libswscale/slice.c
index f9c413cebd..925ce55f30 100644
--- a/libswscale/slice.c
+++ b/libswscale/slice.c
@@ -59,7 +59,7 @@ static int alloc_lines(SwsSlice *s, int size, int width)
         for (j = 0; j < n; ++j) {
             // chroma plane line U and V are expected to be contiguous in memory
             // by mmx vertical scaler code
-            s->plane[i].line[j] = av_malloc(size * 2 + 32);
+            s->plane[i].line[j] = av_mallocz(size * 2 + 32);
             if (!s->plane[i].line[j]) {
                 free_lines(s);
                 return AVERROR(ENOMEM);