# Uneven line spacing and titlesec

I want to set the leading for chapter titles with fontspec and titlesec. Unfortunately, the first line has bigger leading than the others and I dont't know how to fix it. I read about the problem, there was suggested to end the paragraph after the chapter title. But I could not do that with titlesec. A minimal example follows:

\documentclass{book}

\usepackage{blindtext}
\usepackage{titlesec}
\usepackage{fontspec}

\begin{document}
\chapter{A long chapter title with multiple lines}
\blindtext
\end{document}


You're asking a baseline skip of 30pt with a font size of 40pt and this is the cause for the squeezed lines. Use a larger baseline skip:

\documentclass{book}

\usepackage{blindtext}
\usepackage{titlesec}
\usepackage{fontspec}

\titleformat{\chapter}
{}
{0pt}
{\MakeUppercase}

\begin{document}

\chapter{A long chapter title with multiple lines}

\blindtext

\end{document}


Avoid \uppercase and prefer \MakeUppercase.

If you want that reduced leading (I can't see any valid reason for it):

\documentclass{book}

\usepackage{blindtext}
\usepackage{titlesec}
\usepackage{fontspec}

\titleformat{\chapter}