diff --git a/include/magic_enum.hpp b/include/magic_enum.hpp
index 21b070d..6c77000 100644
--- a/include/magic_enum.hpp
+++ b/include/magic_enum.hpp
@@ -138,8 +138,8 @@ using char_type = string_view::value_type;
 static_assert(std::is_same_v<string_view::value_type, string::value_type>, "magic_enum::customize requires same string_view::value_type and string::value_type");
 static_assert([] {
   if constexpr (std::is_same_v<char_type, wchar_t>) {
-    constexpr const char     c[] =  "abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
-    constexpr const wchar_t wc[] = L"abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+    constexpr const char     c[] =  "abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789|";
+    constexpr const wchar_t wc[] = L"abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789|";
     static_assert(std::size(c) == std::size(wc), "magic_enum::customize identifier characters are multichars in wchar_t.");
 
     for (std::size_t i = 0; i < std::size(c); ++i) {
@@ -263,10 +263,10 @@ class static_str {
 
  private:
   template <std::uint16_t... I>
-  constexpr static_str(const char* str, std::integer_sequence<std::uint16_t, I...>) noexcept : chars_{static_cast<char_type>(str[I])..., '\0'} {}
+  constexpr static_str(const char* str, std::integer_sequence<std::uint16_t, I...>) noexcept : chars_{static_cast<char_type>(str[I])..., static_cast<char_type>('\0')} {}
 
   template <std::uint16_t... I>
-  constexpr static_str(string_view str, std::integer_sequence<std::uint16_t, I...>) noexcept : chars_{str[I]..., '\0'} {}
+  constexpr static_str(string_view str, std::integer_sequence<std::uint16_t, I...>) noexcept : chars_{str[I]..., static_cast<char_type>('\0')} {}
 
   char_type chars_[static_cast<std::size_t>(N) + 1];
 };
@@ -290,7 +290,7 @@ class static_str<0> {
 template <typename Op = std::equal_to<>>
 class case_insensitive {
   static constexpr char_type to_lower(char_type c) noexcept {
-    return (c >= 'A' && c <= 'Z') ? static_cast<char_type>(c + ('a' - 'A')) : c;
+    return (c >= static_cast<char_type>('A') && c <= static_cast<char_type>('Z')) ? static_cast<char_type>(c + (static_cast<char_type>('a') - static_cast<char_type>('A'))) : c;
   }
 
  public:
@@ -1234,7 +1234,7 @@ template <detail::enum_subtype S, typename E>
 // Returns name from enum-flags value.
 // If enum-flags value does not have name or value out of range, returns empty string.
 template <typename E>
-[[nodiscard]] auto enum_flags_name(E value, char_type sep = '|') -> detail::enable_if_t<E, string> {
+[[nodiscard]] auto enum_flags_name(E value, char_type sep = static_cast<char_type>('|')) -> detail::enable_if_t<E, string> {
   using D = std::decay_t<E>;
   using U = underlying_type_t<D>;
   constexpr auto S = detail::enum_subtype::flags;
diff --git a/include/magic_enum_containers.hpp b/include/magic_enum_containers.hpp
index a13a6bb..db4e912 100644
--- a/include/magic_enum_containers.hpp
+++ b/include/magic_enum_containers.hpp
@@ -546,7 +546,7 @@ class bitset {
     }
   }
 
-  constexpr explicit bitset(detail::raw_access_t, string_view sv, string_view::size_type pos = 0, string_view::size_type n = string_view::npos, char_type zero = '0', char_type one = '1')
+  constexpr explicit bitset(detail::raw_access_t, string_view sv, string_view::size_type pos = 0, string_view::size_type n = string_view::npos, char_type zero = static_cast<char_type>('0'), char_type one = static_cast<char_type>('1'))
       : a{{}} {
     std::size_t i{};
     for (auto c : sv.substr(pos, n)) {
@@ -562,8 +562,8 @@ class bitset {
     }
   }
 
-  constexpr explicit bitset(detail::raw_access_t, const char_type* str, std::size_t n = ~std::size_t{}, char_type zero = '0', char_type one = '1')
-      : bitset(std::string_view{str, (std::min)(std::char_traits<char_type>::length(str), n)}, 0, n, zero, one) {}
+  constexpr explicit bitset(detail::raw_access_t, const char_type* str, std::size_t n = ~std::size_t{}, char_type zero = static_cast<char_type>('0'), char_type one = static_cast<char_type>('1'))
+      : bitset(string_view{str, (std::min)(std::char_traits<char_type>::length(str), n)}, 0, n, zero, one) {}
 
   constexpr bitset(std::initializer_list<E> starters) : a{{}} {
     if constexpr (magic_enum::detail::subtype_v<E> == magic_enum::detail::enum_subtype::flags) {
@@ -591,7 +591,7 @@ class bitset {
   }
 
   template <typename Cmp = std::equal_to<>>
-  constexpr explicit bitset(string_view sv, Cmp&& cmp = {}, char_type sep = '|') {
+  constexpr explicit bitset(string_view sv, Cmp&& cmp = {}, char_type sep = static_cast<char_type>('|')) {
     for (std::size_t to{}; (to = magic_enum::detail::find(sv, sep)) != string_view::npos; sv.remove_prefix(to + 1)) {
       if (auto v = enum_cast<E>(sv.substr(0, to), cmp)) {
         set(v);
@@ -756,7 +756,7 @@ class bitset {
     return res;
   }
 
-  [[nodiscard]] string to_string(char_type sep = '|') const {
+  [[nodiscard]] string to_string(char_type sep = static_cast<char_type>('|')) const {
     string name;
 
     for (auto& e : enum_values<E>()) {
@@ -771,7 +771,7 @@ class bitset {
     return name;
   }
 
-  [[nodiscard]] string to_string(detail::raw_access_t, char_type zero = '0', char_type one = '1') const {
+  [[nodiscard]] string to_string(detail::raw_access_t, char_type zero = static_cast<char_type>('0'), char_type one = static_cast<char_type>('1')) const {
     string name;
     name.reserve(size());
     for (std::size_t i{}; i < size(); ++i) {