diff --git a/libavformat/avienc.c b/libavformat/avienc.c
index 19cabe2aef..b6b3f2192e 100644
--- a/libavformat/avienc.c
+++ b/libavformat/avienc.c
@@ -558,7 +558,7 @@ static int avi_write_packet(AVFormatContext *s, AVPacket *pkt)
         int cl = idx->entry / AVI_INDEX_CLUSTER_SIZE;
         int id = idx->entry % AVI_INDEX_CLUSTER_SIZE;
         if (idx->ents_allocated <= idx->entry) {
-            idx->cluster = av_realloc(idx->cluster, (cl+1)*sizeof(void*));
+            idx->cluster = av_realloc_f(idx->cluster, sizeof(void*), cl+1);
             if (!idx->cluster)
                 return -1;
             idx->cluster[cl] = av_malloc(AVI_INDEX_CLUSTER_SIZE*sizeof(AVIIentry));