diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 1f372affcb..840484b37e 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -2903,7 +2903,7 @@ static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadF
         meta = NULL;
         ctx  = mxf;
     }
-    while (avio_tell(pb) + 4 < klv_end && !avio_feof(pb)) {
+    while (avio_tell(pb) + 4ULL < klv_end && !avio_feof(pb)) {
         int ret;
         int tag = avio_rb16(pb);
         int size = avio_rb16(pb); /* KLV specified by 0x53 */