You're right. In that case, since bundled file is usually already wrapped into kind of wrapper function (UMD or other; you're not setting strict mode globally anyway, right?), you can set this function to strict mode and pass global object from outside for any internal use:

```javascript
(function (global) {
    'use strict';
    // ... all the real code goes here ...
})((function () { return this })());
```

or

```javascript
(function (factory) {
    // your UMD or other wrapper
    factory(this);
}(function (global) {
    'use strict';
    // ... all the real code goes here ...
});
```