Honda has confirmed that it is taking a more powerful engine to Baku this weekend.
Last week, Red Bull's Dr Helmut Marko said the new engine is 20 horse power better than the power unit used in Melbourne, Bahrain and China.
And Christian Horner said: "There are things in the pipeline that should help us in the near future to find that bit we are missing compared to the cars ahead of us."
Honda's technical director Toyoharu Tanabe has now confirmed: "This weekend, we will introduce the Spec 2 version of our internal combustion engine across all four cars right from the start of the weekend."
He said the new engine will address the problem suffered by Daniil Kvyat in China.
"The main benefits of Spec 2 are improved durability and life and better reliability. It also offers a slight improvement in performance," said Tanabe.
Engine power is important at Baku, whose street layout includes a 2.1km pit straight.