diff --git a/zdump/zg.c b/zdump/zg.c
index 378cbf9b..8f417936 100644
--- a/zdump/zg.c
+++ b/zdump/zg.c
@@ -280,6 +280,9 @@ off_t zg_seek(struct zg_fh *zg_fh, off_t off, enum zg_check check)
 {
 	off_t rc;
 
+	if (off >= zg_fh->sb.st_size)
+		ERR_EXIT("Trying to seek past file end \"%s\"", zg_fh->path);
+
 	rc = lseek(zg_fh->fh, off, SEEK_SET);
 	if (rc == -1 && check != ZG_CHECK_NONE)
 		ERR_EXIT_ERRNO("Could not seek \"%s\"", zg_fh->path);