US green card holders and Canadian visas

While processing my visa for a business trip to our Canadian office, I was directed to the following interesting factoid:

http://www.canadainternational.gc.ca/san_francisco/consul/faq.aspx?view=d

Visas and Immigration

Q. I am a US permanent resident and I hold another country’s valid passport. Do I need a visa to go to Canada?

A. As a US permanent resident (green card holder) you will not need a visa to go to Canada as a tourist. Your green card acts in lieu of a visa but only in conjunction with a valid passport from your country of citizenship.

Looks like that trip to Niagara Falls that we were planning next year won’t be as complicated as I originally thought.

It also means that’s one less visa for me to collect (I’m almost tempted to say bummer).