diff --git a/chapter01.tex b/chapter01.tex
index 60ae11a..8f449ab 100644
--- a/chapter01.tex
+++ b/chapter01.tex
@@ -526,7 +526,7 @@ \subsubsection{Macros}
 
 A better version of the macro is as follows:
 \begin{lstlisting}
-#define SQ(a) (a)*(a)
+#define SQ(a) ((a)*(a))
 \end{lstlisting}
 Now the code
 \begin{lstlisting}