diff --git a/libavformat/mov.c b/libavformat/mov.c
index a77d6908e3..1815a7303f 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -4415,7 +4415,7 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
     if (atom.size < 0)
         atom.size = INT64_MAX;
-    while (total_size + 8 <= atom.size && !avio_feof(pb)) {
+    while (total_size <= atom.size - 8 && !avio_feof(pb)) {
         int (*parse)(MOVContext*, AVIOContext*, MOVAtom) = NULL;
         a.size = atom.size;
         a.type=0;