Using the UDamageType Class

I am trying to add projectiles to my game (bullets that my gun will shoot). I want them to deal damage obviously so I initialized it as followed:

    /** type of damage */
	UPROPERTY(EditDefaultsOnly, Category = WeaponStat)
	TSubclassOf<UDamageType> DamageType;

	/** defaults */
	FProjectileWeaponData()
	{
		ProjectileClass = NULL;
		ProjectileLife = 10.0f;
		ExplosionDamage = 100;
		ExplosionRadius = 300.0f;
		DamageType = UDamageType::StaticClass();
	}

The last line DamageType = UDamageType::StaticClass(); I get an error that says

 "Error: Incomplete type is not allowed"

When I try and run anyways I get the error

"error C2027: use of undefined type 'UDamageType'"

I am using unreal engine 4.4.3 if that helps at all. If anyone knows what is going on please let me know. Thanks for the help!

Did you include DamageType.h?

I tried but is said that no such file existed. I wonder if the header file is called something else.

It’s here:
Runtime/Engine/Classes/GameFramework/DamageType.h

I see I need to type #include “GameFramework/DamageType.h”. That way it knows where to look