diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 6a74c1ce68..9041280e77 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -308,7 +308,7 @@ int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
         ctx->seek_count++;
         if (!s->write_flag)
             s->buf_end = s->buffer;
-        s->buf_ptr = s->buf_ptr_max = s->buffer;
+        s->checksum_ptr = s->buf_ptr = s->buf_ptr_max = s->buffer;
         s->pos = offset;
     }
     s->eof_reached = 0;