diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 1788bf37e..dd5491021 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -2904,6 +2904,7 @@ ngx_http_set_keepalive(ngx_http_request_t *r)
             }
 
             cl->buf = b;
+            cl->next = NULL;
 
             hc->busy = cl;
             hc->nbusy = 1;