Do I need to tell prospective tenants that the house is on the market?

I am between tenants right now and advertising for a new one. I also am in the process of putting my house up for sale...I have about a one year timeline for sale, so I am not in a super rush...I live in the lower half of this property and rent out the upper. I plan to have my unit as the primary showing and viewing of the upper as a second showing only. I ume this will greatly limit the number of times I have to inconvenience the tenants, if at all. With the market as it it, the house could sit for a year or more, and likewise, it may never affect the person coming to rent. Further, regardless of what I do, their lease would trump any sale...I am thinking I won't say anything as I am interviewing folks, but will let them know once they are actually committed. It seems that it might scare someone off (without merit) just because they hear it is "on the market"...what do you think?