Pennsylvania residents who renewed their car registrations this year may have noticed the absence of the little rectangular date stickers for their license plates.

But did you take off the old sticker?

Officials are warning Pennsylvanians, especially those who travel out of state, to tear it off, or risk being pulled over.

The Pennsylvania Department of Transportation stopped issuing the stickers at the end of 2016 in part as a cost-saving measure. It ended a practice that dated back to 1959. The department anticipates saving $3.1 million in the first year.

New Jersey eliminated registration stickers in 2004.

Residents are not required to remove the stickers, according to PennDOT's information page.

State Rep. Justin Simmons recently posted on Facebook for residents to remove their outdated stickers, to avoid being pulled over by police assuming their registration is expired.

PennDOT alerted police from other states and Canada about the lack of registration stickers, Simmons wrote, but some residents have reported being pulled over for "expired" registrations.

The Southern Regional Police Department, which covers communities in York County near the Maryland border, posted a reminder back in August to remove the stickers, after hearing about local drivers being cited.

This agency has received several reports as well as seen discussions on the Southern York County Facebook page regarding... Posted by Southern Regional Police Department - York County on Friday, August 4, 2017

Sarah Cassi may be reached at scassi@lehighvalleylive.com. Follow her on Twitter @SarahCassi. Find lehighvalleylive.com on Facebook.