A Sunday newspaper ad from the electrical workers’ union endorsing Rep. Joe Kennedy III (D-MA) in his bid for Senate botched the spelling of Worcester County, spelling it instead as it is famously mispronounced: “Worchester.”

The full-page ad ran in Sunday’s print edition of the Telegram & Gazette, the newspaper of Worcester County, which is the largest county by area in Massachusetts and the second most populous, per Census Bureau data.

John Walsh, campaign manager for the race’s frontrunner, Sen. Ed Markey (D-MA), took to social media to point out the error:

Massachusetts’ town nomenclature has a reputation for being phonetically challenging, and oftentimes Massachusettsans can identify out-of-towners through their pronunciation blunders. Worcester, pronounced “Wuh-ster” or “Wuh-stuh,” is among a list of several, including Woburn, Tewksbury, Gloucester, Leicester, Tyngsborough, Lowell, Peabody, Norfolk, and Scituate.

“As if his campaign couldn’t get any worse..ter,” one commenter tweeted.

“The disrespect for CMass from the highbrow Eastern Mass elite continues,” another added.

Local 103 IBEW, the Boston chapter of the electrical workers’ union that ran the ad, laid blame on the newspaper, writing in response to the campaign manager, “The T&G apologized for their error. We accept their apology and correction. We’re proud to support JK3 and the T&G. The T&G provides great community journalism”:

The heated primary race taking place Tuesday has gained attention for its unusual intraparty face-off between 39-year-old Kennedy, a scion bearing the dynastic last name of his great uncles President John F. Kennedy and Sen. Ted Kennedy, and 74-year-old Markey, who has served in Congress since 1976.

While Kennedy initially entered the primary last fall with a dramatic double-digit lead, he now trails Markey in most polls and, despite consistently outraising him, now also has about $2.2 million less than Markey in cash on hand.

This latest mishap, although seemingly the fault of Local 103 IBEW or the Telegram & Gazette, will likely not do the congressman any favors as his campaign enters its final stretch.