diff --git a/src/main.tex b/src/main.tex
index 8a5bd16..faf9e48 100644
--- a/src/main.tex
+++ b/src/main.tex
@@ -14,6 +14,7 @@
 \usepackage{indentfirst}
 \usepackage{float}
 \usepackage{geometry}
+\usepackage{listings}
 
 \geometry{
     paper=a4paper,