Disable "Change keyboard" popup from spacebar?

When I hold the spacebar down it gives me this "Change keyboard" popup:
https ://s2.postimg.org/6yc8x68qh/Screenshot_20170812-050429.png
(Remove space. Wasn't able to attach pictures other way.)

It's annoying because it'll popup too easily when I try to move the cursor by sliding my finger on the spacebar. Also, because there's a separate button to bring that popup up (on the bottom right corner), I don't even need it to popup from the spacebar:
https ://s11.postimg.org/ey7d4f16b/Screenshot_20170812-051408_01.png

So, any way to disable it popping up from the spacebar?

I have Android 6.0.1 on Fairphone2 and I use Google keyboard