diff --git a/chapters/unitexpressions.tex b/chapters/unitexpressions.tex
index 2b1814bda..747ffef49 100644
--- a/chapters/unitexpressions.tex
+++ b/chapters/unitexpressions.tex
@@ -69,7 +69,7 @@ \section{The Syntax of Unit Expressions}\label{the-syntax-of-unit-expressions}
    unit_symbol | unit_prefix unit_symbol
 
 unit_prefix:
-   "Y" | "Z" | "E" | "P" | "T" | "G" | "M" | "k" | "h" | "da" 
+   "Y" | "Z" | "E" | "P" | "T" | "G" | "M" | "k" | "h" | "da"
    | "d" | "c | "m" | "u" | "n" | "p" | "f" | "a" | "z" | "y"
 \end{lstlisting}