diff --git a/src/openvic-simulation/core/object/FixedPoint.hpp b/src/openvic-simulation/core/object/FixedPoint.hpp
index 424a15a17..ccb6461d4 100644
--- a/src/openvic-simulation/core/object/FixedPoint.hpp
+++ b/src/openvic-simulation/core/object/FixedPoint.hpp
@@ -9,6 +9,7 @@
 #include <fmt/base.h>
 #include <fmt/format.h>
 
+#include "openvic-simulation/core/Math.hpp"
 #include "openvic-simulation/core/Typedefs.hpp"
 
 namespace OpenVic {