diff --git a/src/time_fugcoeff.cpp b/src/time_fugcoeff.cpp
index e664e1886b844d432e6631fc02ef6e25e2e1426f..b54a5b91011b029c217f1e144c04231511d4a7ac 100644
--- a/src/time_fugcoeff.cpp
+++ b/src/time_fugcoeff.cpp
@@ -14,13 +14,14 @@
 #include <numeric>
 
 #include "teqp/models/multifluid.hpp"
+#include "teqp/derivs.hpp"
 
 int main()
 {
     // You may need to change this path to suit your installation
     // Note: forward-slashes are recommended.
-    std::string path = "C:/Program Files (x86)/REFPROP";
-    std::string DLL_name = "REFPRP64.dll";
+    std::string path = std::getenv("RPPREFIX");
+    std::string DLL_name = "";
 
     // Load the shared library and set up the fluid
     std::string err;