diff --git a/src/http/ngx_http_request_body.c b/src/http/ngx_http_request_body.c
index 89a4c74..ad3549f 100644
--- a/src/http/ngx_http_request_body.c
+++ b/src/http/ngx_http_request_body.c
@@ -1309,7 +1309,7 @@
 
     if (rb->rest > 0) {
 
-        if (rb->buf && rb->buf->last == rb->buf->end
+        if (rb->bufs && rb->buf && rb->buf->last == rb->buf->end
             && ngx_http_write_request_body(r) != NGX_OK)
         {
             return NGX_HTTP_INTERNAL_SERVER_ERROR;