Integrated PayPal Button Comes Up In CAD Instead of USD

For the integrated paypal button I have USD setup but when I click on it, it says 39.99 CAD instead of USD. This is bad because the price has always been this so I don’t want to change it but since a Canadian dollar is only 90 cents for every US dollar, I’d be losing money. Is this broken or why does it show up in CAD?