diff --git a/doc/CodingGuidelines.lyx b/doc/CodingGuidelines.lyx
index ce083df6c..caaf27d8e 100644
--- a/doc/CodingGuidelines.lyx
+++ b/doc/CodingGuidelines.lyx
@@ -5,6 +5,7 @@
 \textclass article
 \begin_preamble
 \usepackage{color}
+\usepackage{listings}
 
 \definecolor{mygreen}{rgb}{0,0.6,0}
 \definecolor{mygray}{rgb}{0.5,0.5,0.5}