Scrutiny comes down hard on the families of US politicians, and most of all on the presidency and its hopefuls. Twenty-five years ago, George H. W. Bush knew that lesson well.

A 1988 letter (pdf) from Bush Sr. warns his son, who would later serve two terms himself, against the appearance of wielding family influence. The New York Times wrote about the letter in 2015, and reporter Eric Lipton tweeted it out again today.

In the missive, Bush Sr. writes that new “friends” may pop up as his presidential candidacy ramped up, and that these friends—genuine or otherwise—may ask for favors. He implored his son: Do not make calls for them.

If there is a legitimate inquiry, call my office. It is certainly appropriate to contact your own government, but let’s do it through my office so no one can accuse any of the family of trying to use influence.

Bush adds, “Every effort will be made to find some phone call, some inquiry, some letter that can be made to appear improper.”

The letter is dated May 8, when George H.W. Bush was running for president for the first time and George W., then 41, was working on his father’s campaign. Bush Sr. sent the same memo to his siblings and to his other children.

Across their three terms, father and son maintained a relatively clean image when it came to conflicts of interest, and Bush’s warnings present a stark contrast to president-elect Donald Trump. Throughout his transition, Trump’s conflicts of interest have been front and center. His first meeting with a foreign head of state, days after the election, included daughter Ivanka Trump, who oversees her father’s private business interests. Ivanka was also on the phone when Trump called Argentinian president Mauricio Macri, and had a prime seat at the table when Trump met US tech executives in his office on Dec. 14.

Trump has tweeted that he will be leaving his businesses “in total” when he assumes the presidency, but how exactly remains unclear. A Dec. 15 press conference to address his divestment plans in detail was canceled and rescheduled for January.