CI Upgrade - A non well formed numeric value encountered

I just upgraded CI from 4.0.3 to 4.1.4,

I get an error setting the expiration of my session after a CI upgrade:

Code:

A non well formed numeric value encountered search →
SYSTEMPATH/Session/Session.php at line 189

          $this->cookie = new Cookie($this->sessionCookieName, '', [
189             'expires'  => $this->sessionExpiration === 0 ? 0 : time() + $this->sessionExpiration,

It thinks sessionExpiration is a string and barfs converting it? In my .env file I've got:
app.sessionExpiration = 259200;

PHP shouldn't have any problem with this.

Simpler is always better

Remove the semicolon after 259200

Duh! Thanks! I wonder why it worked before.

Simpler is always better