diff --git a/libs/ftl/enum_test.cpp b/libs/ftl/enum_test.cpp
index 1fd43ab..d8ce7a5 100644
--- a/libs/ftl/enum_test.cpp
+++ b/libs/ftl/enum_test.cpp
@@ -72,7 +72,7 @@
   kNeptune
 };
 
-constexpr Planet kPluto{ftl::enum_cast(Planet::kNeptune) + 1};  // Honorable mention.
+constexpr Planet kPluto{ftl::to_underlying(Planet::kNeptune) + 1};  // Honorable mention.
 
 static_assert(ftl::enum_begin_v<Planet> == Planet::kMercury);
 static_assert(ftl::enum_last_v<Planet> == Planet::kNeptune);