diff --git a/include/math/math.hpp b/include/math/math.hpp
index 2277b3e..8b8e337 100644
--- a/include/math/math.hpp
+++ b/include/math/math.hpp
@@ -19,6 +19,7 @@
 #ifndef REXY_MATH_HPP
 #define REXY_MATH_HPP
 
+#include "fwd_declare.hpp"
 #include "math_common.hpp"
 #include "vec.hpp"
 #include "mat.hpp"