Decrease Global Cooldown Spells With Haste

[Ikopdoa]

The more haste you got the less is the global cooldown. Right? That's atleast how it used to be on Mond WoW 4.0.6 if anyone remembers back then. Oooooooonce again, I'm using Jack Sparrow's Mond WoW Source.
https://www.emucoach.com/showthread.php/5302-Release-Mond-WoW-Source-precompiled-binaries

What do I have to do to achieve something like this? Do I have to edit something in Spell.cpp? I have tried changing

// Global cooldowns management
enum GCDLimits
{
	MIN_GCD = 1000,
	MAX_GCD = 1500
};

to

// Global cooldowns management
enum GCDLimits
{
	MIN_GCD = 800,
	MAX_GCD = 500
};

nothing has changed ingame though. Does someone know what to do?