diff --git a/src/app.cpp b/src/app.cpp
index d908de7..9113921 100644
--- a/src/app.cpp
+++ b/src/app.cpp
@@ -1,3 +1,4 @@
+#define _USE_MATH_DEFINES
 #include "app.hpp"
 #include <algorithm>
 #include <sstream>