President Trump’s approval rating dropped slightly, to 37 percent, following a week of explosive allegations detailed in a new book about the Trump administration, according to a poll released Monday.

The first Gallup poll of 2018 shows Trump’s approval rating dipped 2 percentage points in the last week. A Dec. 31 poll showed Trump with a 39 percent approval rating, his highest mark in months. 

In the week since, Michael Wolff’s book, “Fire and Fury: Inside the Trump White House,” has been released, which contains numerous allegations about the Trump White House and sparked a public rift between the president and his former chief strategist, Stephen Bannon. 

Trump has lashed out at the book, calling Wolff a “fraud” and deeming the work a “fake book.”

In response to questions raised by the book that he is ill-equipped for the presidency, Trump defended his mental stability, calling himself a “very stable genius.” 

Gallup announced last week it will no longer issue daily updates on presidential job approval ratings. Instead the group will update its polls on a weekly basis.

The shift results from a change in surveying methods, Gallup said.