diff --git a/src/core/include/units/unit.h b/src/core/include/units/unit.h
index f5d14220..c429f837 100644
--- a/src/core/include/units/unit.h
+++ b/src/core/include/units/unit.h
@@ -126,7 +126,7 @@ struct prefixed_unit : downcast_dispatch<Child, scaled_unit<P::mag * U::mag, typ
  * @tparam Child inherited class type used by the downcasting facility (CRTP Idiom)
  */
 template<typename Child>
-struct derived_unit : downcast_dispatch<Child, scaled_unit<ratio(1), Child>> {};
+struct derived_unit : downcast_dispatch<Child, scaled_unit<as_magnitude<1>(), Child>> {};
 
 /**
  * @brief A unit with a deduced ratio and symbol
@@ -195,8 +195,8 @@ namespace detail {
 template<typename Child, basic_symbol_text Symbol>
 void is_named_impl(const volatile named_unit<Child, Symbol>*);
 
-template<typename Child, basic_symbol_text Symbol, ratio R, typename U>
-void is_named_impl(const volatile named_scaled_unit<Child, Symbol, R, U>*);
+template<typename Child, basic_symbol_text Symbol, Magnitude auto M, typename U>
+void is_named_impl(const volatile named_scaled_unit<Child, Symbol, M, U>*);
 
 template<typename Child, typename P, typename U>
 void is_named_impl(const volatile prefixed_unit<Child, P, U>*);
@@ -213,8 +213,8 @@ inline constexpr bool is_named<U> = requires(U * u) { is_named_impl(u); };
 template<typename Child, basic_symbol_text Symbol>
 void can_be_prefixed_impl(const volatile named_unit<Child, Symbol>*);
 
-template<typename Child, basic_symbol_text Symbol, ratio R, typename U>
-void can_be_prefixed_impl(const volatile named_scaled_unit<Child, Symbol, R, U>*);
+template<typename Child, basic_symbol_text Symbol, Magnitude auto M, typename U>
+void can_be_prefixed_impl(const volatile named_scaled_unit<Child, Symbol, M, U>*);
 
 template<typename U, basic_symbol_text Symbol>
 void can_be_prefixed_impl(const volatile alias_unit<U, Symbol>*);
@@ -222,8 +222,8 @@ void can_be_prefixed_impl(const volatile alias_unit<U, Symbol>*);
 template<Unit U>
 inline constexpr bool can_be_prefixed<U> = requires(U * u) { can_be_prefixed_impl(u); };
 
-template<ratio R, typename U>
-inline constexpr bool can_be_prefixed<scaled_unit<R, U>> = can_be_prefixed<typename U::reference>;
+template<Magnitude auto M, typename U>
+inline constexpr bool can_be_prefixed<scaled_unit<M, U>> = can_be_prefixed<typename U::reference>;
 
 }  // namespace detail
 
diff --git a/src/systems/si-fps/include/units/isq/si/fps/length.h b/src/systems/si-fps/include/units/isq/si/fps/length.h
index 35f51d7f..04a9e930 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/length.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/length.h
@@ -39,6 +39,7 @@ using si::international::fathom;
 using si::international::foot;
 using si::international::inch;
 using si::international::mil;
+using si::international::mile;
 using si::international::thou;
 using si::international::yard;
 
@@ -47,8 +48,6 @@ struct thousandth : alias_unit<thou, "thou"> {};
 
 struct kiloyard : prefixed_unit<kiloyard, si::kilo, yard> {};
 
-struct mile : named_scaled_unit<mile, "mile", as_magnitude<5'280>(), foot> {};
-
 struct nautical_mile : named_scaled_unit<nautical_mile, "nmi", as_magnitude<2'000>(), yard> {};
 
 struct dim_length : isq::dim_length<foot> {};
diff --git a/test/unit_test/runtime/fmt_units_test.cpp b/test/unit_test/runtime/fmt_units_test.cpp
index 22c04fe2..58531174 100644
--- a/test/unit_test/runtime/fmt_units_test.cpp
+++ b/test/unit_test/runtime/fmt_units_test.cpp
@@ -66,7 +66,7 @@ TEST_CASE("std::format on synthesized unit symbols", "[text][fmt]")
     CHECK(STD_FMT::format("{}", 1_q_fathom_us) == "1 fathom(us)");
     CHECK(STD_FMT::format("{}", 1_q_mi) == "1 mi");
     CHECK(STD_FMT::format("{}", 1_q_mi_us) == "1 mi(us)");
-    CHECK(STD_FMT::format("{}", 1_q_naut_mi) == "1 nmi");
+    CHECK(STD_FMT::format("{}", 1_q_naut_mi) == "1 mi(naut)");
     CHECK(STD_FMT::format("{}", 1_q_ch) == "1 ch");
     CHECK(STD_FMT::format("{}", 1_q_rd) == "1 rd");
     CHECK(STD_FMT::format("{}", 1_q_thou) == "1 thou");