Some Montreal landlords are banning the use of cannabis in their rental units.

As the likely legalization of marijuana looms, many are currently renewing leases with a new clause that forbids tenants from smoking up.

Rental property owners are asking tenants to sign new leases which would include a ban on smoking cannabis anywhere on the property.

Landlords say they’re concerned the legalization of marijuana will cause a problem akin to complaints from neighbours about noise or cigarette smoking.

If the smell is too strong, just like if noise is too loud, it can be considered a nuisance that affects the quality of life of the other tenants.

Landlord Christian Perron said tenants who are annoyed by marijuana smoke could see their rent reduced.

"He can go to the Regie du Logement to get a reduction of his rent, so we don't want that," said Perron.

Roughly 400 landlords in Montreal are trying to actively prevent this scenario if and when marijuana becomes legalized by the federal government, predicted to happen this spring.

Landlords say they are not concerned that more people will be smoking pot, but instead they fear that as it becomes legalized, they will have less power to stop it.

"Now it’s illegal, so when I knock at your door, I can tell you, ‘Hey, you can’t smoke illegal products,’ so it’s easy, but when it will be legalized what are we going to do? So we’d prefer to prevent it," said Perron.

Marijuana advocate Adam Greenblatt believes this is an overreaction.

"This is a knee-jerk, prohibitionist measure put forward by this landlords' association," said Greenblatt.

"What I would like to see is proactive rules put forward by municipalities."

He said the anti-marijuana clause could be discriminatory against those who use medical marijuana.

Other landlords said they are worried that more people will begin growing pot at home.

"Growing and smoking marijuana for medical purposes we understand that it can be allowed but it's not more important than the rights of other tenants," said Hans Brouillette.

"Our position is that now growing plants should be allowed in apartments."

There is a catch in the new clause: Tenants are not required to sign the clause, because legally, whatever terms they agreed to in their original lease are the terms which stand.

If there is no smoking ban in their current lease, the landlord cannot force a tenant to comply.

This isn’t a concern for the majority of landlords: 60 per cent of Quebec landlords have already included full or partial smoking bans in their leases. The difficulty in these cases, however, is enforcing it.

Issues such as growing marijuana and medical marijuana are all also issues landlords and tenants will have to sort through.