diff --git a/turtle/detail/function.hpp b/turtle/detail/function.hpp
index 007aa77..d9fea6d 100644
--- a/turtle/detail/function.hpp
+++ b/turtle/detail/function.hpp
@@ -39,7 +39,7 @@
 #undef MOCK_NUM_ARGS_0
 #undef MOCK_NUM_ARGS
 
-#define BOOST_PP_FILENAME_1 "turtle/detail/function_iterate.hpp"
+#define BOOST_PP_FILENAME_1 <turtle/detail/function_iterate.hpp>
 #define BOOST_PP_ITERATION_LIMITS (1, MOCK_MAX_ARGS)
 #include BOOST_PP_ITERATE()
 #undef BOOST_PP_FILENAME_1