diff --git a/lib/transfer.c b/lib/transfer.c
index bc7ff432628a7667cff8a96a054a96e05be68e4b..8fd421aaea03ebde9578fa2654539404b935cab0 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -609,7 +609,7 @@ CURLcode Curl_readwrite(struct connectdata *conn,
             char *start;
 
             /* Find the first non-space letter */
-            for(start=k->p+18;
+            for(start=k->p+17;
                 *start && isspace((int)*start);
                 start++);