diff --git a/lib/urldata.h b/lib/urldata.h
index c6d861621..ad6161dfa 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -656,7 +656,7 @@ struct HandleData {
   curl_off_t size;        /* -1 if unknown at this point */
   curl_off_t *bytecountp; /* return number of bytes read or NULL */
 
-  curl_off_t maxdownload; /* in bytes, the maximum amount of data to fetch, 0
+  curl_off_t maxdownload; /* in bytes, the maximum amount of data to fetch, -1
                              means unlimited */
   curl_off_t *writebytecountp; /* return number of bytes written or NULL */