diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index ffdffcf07..d99d85454 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -2456,7 +2456,9 @@ ngx_http_upstream_upgrade(ngx_http_request_t *r, ngx_http_upstream_t *u)
     if (u->peer.connection->read->ready
         || u->buffer.pos != u->buffer.last)
     {
+        ngx_post_event(c->read, &ngx_posted_events);
         ngx_http_upstream_process_upgraded(r, 1, 1);
+        return;
     }
 
     ngx_http_upstream_process_upgraded(r, 0, 1);