diff --git a/examples/usertype_special_functions.cpp b/examples/usertype_special_functions.cpp
index 7121fe9c..ef1492df 100644
--- a/examples/usertype_special_functions.cpp
+++ b/examples/usertype_special_functions.cpp
@@ -2,6 +2,7 @@
 #include <sol.hpp>
 #include <iostream>
 #include <cassert>
+#include <cmath>
 
 struct vec {
 	double x;