diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index ff7460e44..5280ac4b9 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -1860,11 +1860,9 @@ ngx_http_proxy_process_status_line(ngx_http_request_t *r)
         }
 #endif
 
-        r->http_version = NGX_HTTP_VERSION_9;
-        u->state->status = NGX_HTTP_OK;
         u->headers_in.connection_close = 1;
 
-        return NGX_OK;
+        return NGX_HTTP_UPSTREAM_INVALID_HEADER;
     }
 
     if (u->state && u->state->status == 0) {