diff --git a/src/core/include/units/unit.h b/src/core/include/units/unit.h
index 3466a86d..03eebcfe 100644
--- a/src/core/include/units/unit.h
+++ b/src/core/include/units/unit.h
@@ -581,11 +581,11 @@ enum class text_encoding {
   default_encoding = unicode
 };
 
-enum class unit_symbol_denominator {
-  solidus_one,      // m/s;   kg m-1 s-1
-  always_solidus,   // m/s;   kg/(m s)
-  always_negative,  // m s-1; kg m-1 s-1
-  default_denominator = solidus_one
+enum class unit_symbol_solidus {
+  one_denominator,  // m/s;   kg m-1 s-1
+  always,           // m/s;   kg/(m s)
+  never,            // m s-1; kg m-1 s-1
+  default_denominator = one_denominator
 };
 
 enum class unit_symbol_separator {
@@ -596,7 +596,7 @@ enum class unit_symbol_separator {
 
 struct unit_symbol_formatting {
   text_encoding encoding = text_encoding::default_encoding;
-  unit_symbol_denominator denominator = unit_symbol_denominator::default_denominator;
+  unit_symbol_solidus solidus = unit_symbol_solidus::default_denominator;
   unit_symbol_separator separator = unit_symbol_separator::default_separator;
 };
 
@@ -749,22 +749,22 @@ constexpr Out unit_symbol_impl(Out out, const type_list<Nums...>& nums, const ty
     // no denominator
     return unit_symbol_impl<CharT>(out, nums, std::index_sequence_for<Nums...>(), fmt, false);
   } else {
-    using enum unit_symbol_denominator;
+    using enum unit_symbol_solidus;
     if constexpr (sizeof...(Nums) > 0) {
       unit_symbol_impl<CharT>(out, nums, std::index_sequence_for<Nums...>(), fmt, false);
     }
 
-    if (fmt.denominator == always_solidus || (fmt.denominator == solidus_one && sizeof...(Dens) == 1)) {
+    if (fmt.solidus == always || (fmt.solidus == one_denominator && sizeof...(Dens) == 1)) {
       if constexpr (sizeof...(Nums) == 0) *out++ = '1';
       *out++ = '/';
     } else {
       out = print_separator<CharT>(out, fmt);
     }
 
-    if (fmt.denominator == always_solidus && sizeof...(Dens) > 1) *out++ = '(';
-    bool negative_power = fmt.denominator == always_negative || (fmt.denominator == solidus_one && sizeof...(Dens) > 1);
+    if (fmt.solidus == always && sizeof...(Dens) > 1) *out++ = '(';
+    bool negative_power = fmt.solidus == never || (fmt.solidus == one_denominator && sizeof...(Dens) > 1);
     out = unit_symbol_impl<CharT>(out, dens, std::index_sequence_for<Dens...>(), fmt, negative_power);
-    if (fmt.denominator == always_solidus && sizeof...(Dens) > 1) *out++ = ')';
+    if (fmt.solidus == always && sizeof...(Dens) > 1) *out++ = ')';
     return out;
   }
 }
diff --git a/test/unit_test/static/unit_test.cpp b/test/unit_test/static/unit_test.cpp
index da71436e..9ead5e96 100644
--- a/test/unit_test/static/unit_test.cpp
+++ b/test/unit_test/static/unit_test.cpp
@@ -482,7 +482,7 @@ static_assert(
 #ifdef __cpp_lib_constexpr_string
 
 using enum text_encoding;
-using enum unit_symbol_denominator;
+using enum unit_symbol_solidus;
 using enum unit_symbol_separator;
 
 // named units
@@ -514,42 +514,36 @@ static_assert(unit_symbol(kilometre * metre) == "km m");
 static_assert(unit_symbol(kilometre * metre, {.separator = dot}) == "km⋅m");
 static_assert(unit_symbol(metre / metre) == "");
 static_assert(unit_symbol(kilometre / metre) == "km/m");
-static_assert(unit_symbol(kilometre / metre, {.denominator = always_negative}) == "km m⁻¹");
-static_assert(unit_symbol(kilometre / metre, {.encoding = ascii, .denominator = always_negative}) == "km m^-1");
+static_assert(unit_symbol(kilometre / metre, {.solidus = never}) == "km m⁻¹");
+static_assert(unit_symbol(kilometre / metre, {.encoding = ascii, .solidus = never}) == "km m^-1");
 static_assert(unit_symbol(metre / second) == "m/s");
-static_assert(unit_symbol(metre / second, {.denominator = always_solidus}) == "m/s");
-static_assert(unit_symbol(metre / second, {.denominator = always_negative}) == "m s⁻¹");
-static_assert(unit_symbol(metre / second, {.encoding = ascii, .denominator = always_negative}) == "m s^-1");
-static_assert(unit_symbol(metre / second, {.denominator = always_negative, .separator = dot}) == "m⋅s⁻¹");
+static_assert(unit_symbol(metre / second, {.solidus = always}) == "m/s");
+static_assert(unit_symbol(metre / second, {.solidus = never}) == "m s⁻¹");
+static_assert(unit_symbol(metre / second, {.encoding = ascii, .solidus = never}) == "m s^-1");
+static_assert(unit_symbol(metre / second, {.solidus = never, .separator = dot}) == "m⋅s⁻¹");
 static_assert(unit_symbol(metre / square<second>) == "m/s²");
 static_assert(unit_symbol(metre / square<second>, {.encoding = ascii}) == "m/s^2");
-static_assert(unit_symbol(metre / square<second>, {.denominator = always_solidus}) == "m/s²");
-static_assert(unit_symbol(metre / square<second>, {.encoding = ascii, .denominator = always_solidus}) == "m/s^2");
-static_assert(unit_symbol(metre / square<second>, {.denominator = always_negative}) == "m s⁻²");
-static_assert(unit_symbol(metre / square<second>, {.encoding = ascii, .denominator = always_negative}) == "m s^-2");
-static_assert(unit_symbol(metre / square<second>, {.denominator = always_negative, .separator = dot}) == "m⋅s⁻²");
+static_assert(unit_symbol(metre / square<second>, {.solidus = always}) == "m/s²");
+static_assert(unit_symbol(metre / square<second>, {.encoding = ascii, .solidus = always}) == "m/s^2");
+static_assert(unit_symbol(metre / square<second>, {.solidus = never}) == "m s⁻²");
+static_assert(unit_symbol(metre / square<second>, {.encoding = ascii, .solidus = never}) == "m s^-2");
+static_assert(unit_symbol(metre / square<second>, {.solidus = never, .separator = dot}) == "m⋅s⁻²");
 static_assert(unit_symbol(kilogram * metre / square<second>) == "kg m/s²");
 static_assert(unit_symbol(kilogram * metre / square<second>, {.separator = dot}) == "kg⋅m/s²");
 static_assert(unit_symbol(kilogram * metre / square<second>, {.encoding = ascii}) == "kg m/s^2");
-static_assert(unit_symbol(kilogram * metre / square<second>, {.denominator = always_solidus}) == "kg m/s²");
-static_assert(unit_symbol(kilogram * metre / square<second>, {.encoding = ascii, .denominator = always_solidus}) ==
-              "kg m/s^2");
-static_assert(unit_symbol(kilogram * metre / square<second>, {.denominator = always_negative}) == "kg m s⁻²");
-static_assert(unit_symbol(kilogram * metre / square<second>, {.encoding = ascii, .denominator = always_negative}) ==
-              "kg m s^-2");
-static_assert(unit_symbol(kilogram * metre / square<second>, {.denominator = always_negative, .separator = dot}) ==
-              "kg⋅m⋅s⁻²");
+static_assert(unit_symbol(kilogram * metre / square<second>, {.solidus = always}) == "kg m/s²");
+static_assert(unit_symbol(kilogram * metre / square<second>, {.encoding = ascii, .solidus = always}) == "kg m/s^2");
+static_assert(unit_symbol(kilogram * metre / square<second>, {.solidus = never}) == "kg m s⁻²");
+static_assert(unit_symbol(kilogram * metre / square<second>, {.encoding = ascii, .solidus = never}) == "kg m s^-2");
+static_assert(unit_symbol(kilogram * metre / square<second>, {.solidus = never, .separator = dot}) == "kg⋅m⋅s⁻²");
 static_assert(unit_symbol(kilogram / metre / square<second>) == "kg m⁻¹ s⁻²");
 static_assert(unit_symbol(kilogram / metre / square<second>, {.separator = dot}) == "kg⋅m⁻¹⋅s⁻²");
 static_assert(unit_symbol(kilogram / metre / square<second>, {.encoding = ascii}) == "kg m^-1 s^-2");
-static_assert(unit_symbol(kilogram / metre / square<second>, {.denominator = always_solidus}) == "kg/(m s²)");
-static_assert(unit_symbol(kilogram / metre / square<second>, {.encoding = ascii, .denominator = always_solidus}) ==
-              "kg/(m s^2)");
-static_assert(unit_symbol(kilogram / metre / square<second>, {.denominator = always_negative}) == "kg m⁻¹ s⁻²");
-static_assert(unit_symbol(kilogram / metre / square<second>, {.encoding = ascii, .denominator = always_negative}) ==
-              "kg m^-1 s^-2");
-static_assert(unit_symbol(kilogram / metre / square<second>, {.denominator = always_negative, .separator = dot}) ==
-              "kg⋅m⁻¹⋅s⁻²");
+static_assert(unit_symbol(kilogram / metre / square<second>, {.solidus = always}) == "kg/(m s²)");
+static_assert(unit_symbol(kilogram / metre / square<second>, {.encoding = ascii, .solidus = always}) == "kg/(m s^2)");
+static_assert(unit_symbol(kilogram / metre / square<second>, {.solidus = never}) == "kg m⁻¹ s⁻²");
+static_assert(unit_symbol(kilogram / metre / square<second>, {.encoding = ascii, .solidus = never}) == "kg m^-1 s^-2");
+static_assert(unit_symbol(kilogram / metre / square<second>, {.solidus = never, .separator = dot}) == "kg⋅m⁻¹⋅s⁻²");
 static_assert(unit_symbol(pow<123>(metre)) == "m¹²³");
 static_assert(unit_symbol(pow<1, 2>(metre)) == "m^(1/2)");
 static_assert(unit_symbol(pow<3, 5>(metre)) == "m^(3/5)");