diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c
index baede5ba20..71e65f4763 100644
--- a/libavformat/asfdec_o.c
+++ b/libavformat/asfdec_o.c
@@ -1361,6 +1361,8 @@ static int asf_read_packet_header(AVFormatContext *s)
     unsigned char error_flags, len_flags, pay_flags;
 
     asf->packet_offset = avio_tell(pb);
+    if (asf->packet_offset > INT64_MAX/2)
+        asf->packet_offset = 0;
     error_flags = avio_r8(pb); // read Error Correction Flags
     if (error_flags & ASF_PACKET_FLAG_ERROR_CORRECTION_PRESENT) {
         if (!(error_flags & ASF_ERROR_CORRECTION_LENGTH_TYPE)) {