diff --git a/libavformat/mov.c b/libavformat/mov.c
index 050857cf8a..e5dd1bd3fa 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -556,7 +556,7 @@ static int mov_read_hdlr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     AVStream *st;
     uint32_t type;
     uint32_t av_unused ctype;
-    int title_size;
+    int64_t title_size;
     char *title_str;
 
     if (c->fc->nb_streams < 1) // meta before first trak
@@ -594,9 +594,10 @@ static int mov_read_hdlr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             return AVERROR(ENOMEM);
         avio_read(pb, title_str, title_size);
         title_str[title_size] = 0;
-        if (title_str[0])
-            av_dict_set(&st->metadata, "handler_name", title_str +
-                        (!c->isom && title_str[0] == title_size - 1), 0);
+        if (title_str[0]) {
+            int off = (!c->isom && title_str[0] == title_size - 1);
+            av_dict_set(&st->metadata, "handler_name", title_str + off, 0);
+        }
         av_freep(&title_str);
     }