diff --git a/ray-tracing-overview/whitted.cpp b/ray-tracing-overview/whitted.cpp
index b1b95c0..880213b 100644
--- a/ray-tracing-overview/whitted.cpp
+++ b/ray-tracing-overview/whitted.cpp
@@ -37,6 +37,8 @@
 #include <iostream>
 #include <fstream>
 #include <cmath>
+#include <cstring>
+#include <limits>
 
 const float kInfinity = std::numeric_limits<float>::max();