webpack ts-loader - typechecking without compilation/transpilation?

Question

I'm using webpack, babel and few custom loaders (that can handle ES6):

                              (still es6)
file_es6.js  -->  my-loaders  ---------->  babel  -->  es5

Now I want to use a typescript loader, and here's where problems started.

I thought that ts-loader will just do type checking and output code stripped of types (code which my loaders can handle). Unfortunately, ts-loader also compiles the code, which I don't want at his step:

                            (compiled junk)
file_es6.ts  -->  ts-loader -------------->  my-loaders  --> babel

Is there a way to completely disable compilation or do I need to rewrite my loaders so they can handle typescript syntax?

I tried to work around it by setting "target": "ESNext" (tsconfig.json) but it still changes code a little bit (and adds "helpers" to the beginning of the code):

 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};

import React from 'react';
import { bindActionCreators } from 'redux';
import styled from 'styled-components';