diff --git a/libavformat/mov.c b/libavformat/mov.c
index a59c804d16..4e68532b69 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2342,7 +2342,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 uint32_t format = AV_RB32(st->codecpar->extradata + 22);
                 if (format == AV_RB32("name") && (int64_t)size >= (int64_t)len + 18) {
                     uint16_t str_size = AV_RB16(st->codecpar->extradata + 26); /* string length */
-                    if (str_size > 0 && size >= (int)str_size + 26) {
+                    if (str_size > 0 && size >= (int)str_size + 30) {
                         char *reel_name = av_malloc(str_size + 1);
                         if (!reel_name)
                             return AVERROR(ENOMEM);