diff --git a/libavformat/mov.c b/libavformat/mov.c
index e9b6c761f4..0ce63209dd 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -179,8 +179,10 @@ static int mov_read_default(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
                 break;
         }
         a.size -= 8;
-        if(a.size < 0 || a.size > atom.size - total_size)
+        if(a.size < 0)
             break;
+        if (a.size > atom.size - total_size)
+            a.size = atom.size - total_size;
 
         for (i = 0; c->parse_table[i].type != 0L
              && c->parse_table[i].type != a.type; i++)