diff --git a/src/core-fmt/include/units/bits/fmt.h b/src/core-fmt/include/units/bits/fmt.h
index 457c87ff..7faa182a 100644
--- a/src/core-fmt/include/units/bits/fmt.h
+++ b/src/core-fmt/include/units/bits/fmt.h
@@ -52,11 +52,11 @@ private:
   unsigned char size_ = 1;
 
 public:
-  constexpr void operator=(std::basic_string_view<Char> s)
+  constexpr void operator=(std::basic_string_view<Char> str)
   {
-    auto size = s.size();
+    auto size = str.size();
     if (size > max_size) return throw STD_FMT::format_error("invalid fill");
-    for (size_t i = 0; i < size; ++i) data_[i] = s[i];
+    for (size_t i = 0; i < size; ++i) data_[i] = str[i];
     size_ = static_cast<unsigned char>(size);
   }
 
diff --git a/src/core-fmt/include/units/format.h b/src/core-fmt/include/units/format.h
index 5e97e4d5..d02c36d2 100644
--- a/src/core-fmt/include/units/format.h
+++ b/src/core-fmt/include/units/format.h
@@ -319,7 +319,7 @@ private:
     constexpr void on_fill(std::basic_string_view<CharT> fill) { f.specs.global.fill = fill; }
     constexpr void on_align(units::detail::fmt_align align) { f.specs.global.align = align; }
     constexpr void on_width(int width) { f.specs.global.width = width; }
-    constexpr void on_sign(units::detail::fmt_sign s) { f.specs.rep.sign = s; }
+    constexpr void on_sign(units::detail::fmt_sign sign) { f.specs.rep.sign = sign; }
     constexpr void on_hash() { f.specs.rep.alt = true; }
     constexpr void on_precision(int precision) { f.specs.rep.precision = precision; }
     constexpr void on_localized() { f.specs.rep.localized = true; }
diff --git a/src/core/include/units/symbol_text.h b/src/core/include/units/symbol_text.h
index dc65443f..3f3466c1 100644
--- a/src/core/include/units/symbol_text.h
+++ b/src/core/include/units/symbol_text.h
@@ -66,12 +66,12 @@ struct basic_symbol_text {
   basic_fixed_string<StandardCharT, N> standard_;
   basic_fixed_string<char, M> ascii_;
 
-  constexpr basic_symbol_text(char s) noexcept: standard_(s), ascii_(s) { detail::validate_ascii_char(s); }
-  constexpr basic_symbol_text(StandardCharT s, char a) noexcept: standard_(s), ascii_(a) { detail::validate_ascii_char(a); }
-  constexpr basic_symbol_text(const char (&s)[N + 1]) noexcept: standard_(s), ascii_(s) { detail::validate_ascii_string<N>(s); }
-  constexpr basic_symbol_text(const basic_fixed_string<char, N>& s) noexcept: standard_(s), ascii_(s) { detail::validate_ascii_string<N>(s.data_); }
-  constexpr basic_symbol_text(const StandardCharT (&s)[N + 1], const char (&a)[M + 1]) noexcept: standard_(s), ascii_(a) { detail::validate_ascii_string<M>(a); }
-  constexpr basic_symbol_text(const basic_fixed_string<StandardCharT, N>& s, const basic_fixed_string<char, M>& a) noexcept: standard_(s), ascii_(a) { detail::validate_ascii_string<M>(a.data_); }
+  constexpr basic_symbol_text(char std) noexcept: standard_(std), ascii_(std) { detail::validate_ascii_char(std); }
+  constexpr basic_symbol_text(StandardCharT std, char a) noexcept: standard_(std), ascii_(a) { detail::validate_ascii_char(a); }
+  constexpr basic_symbol_text(const char (&std)[N + 1]) noexcept: standard_(std), ascii_(std) { detail::validate_ascii_string<N>(std); }
+  constexpr basic_symbol_text(const basic_fixed_string<char, N>& std) noexcept: standard_(std), ascii_(std) { detail::validate_ascii_string<N>(std.data_); }
+  constexpr basic_symbol_text(const StandardCharT (&std)[N + 1], const char (&a)[M + 1]) noexcept: standard_(std), ascii_(a) { detail::validate_ascii_string<M>(a); }
+  constexpr basic_symbol_text(const basic_fixed_string<StandardCharT, N>& std, const basic_fixed_string<char, M>& a) noexcept: standard_(std), ascii_(a) { detail::validate_ascii_string<M>(a.data_); }
 
   [[nodiscard]] constexpr auto& standard() { return standard_; }
   [[nodiscard]] constexpr const auto& standard() const { return standard_; }