diff --git a/libavformat/mov.c b/libavformat/mov.c
index 2712364f4d..3843cebe67 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2336,7 +2336,7 @@ static int mov_read_stsd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     if (!sc->extradata)
         return AVERROR(ENOMEM);
 
-    sc->extradata_size = av_mallocz_array(sc->stsd_count, sizeof(sc->extradata_size));
+    sc->extradata_size = av_mallocz_array(sc->stsd_count, sizeof(*sc->extradata_size));
     if (!sc->extradata_size)
         return AVERROR(ENOMEM);