diff --git a/src/color_registry.cc b/src/color_registry.cc
index 1d1b3235..360e08f4 100644
--- a/src/color_registry.cc
+++ b/src/color_registry.cc
@@ -42,7 +42,7 @@ void ColorRegistry::register_alias(const String& name, const String& colordesc,
        throw runtime_error("alias '" + name + "' already defined");
 
     if (std::find_if(name.begin(), name.end(),
-                     [](Character c) { return not isalnum(c); }) != name.end())
+                     [](char c) { return not isalnum(c); }) != name.end())
         throw runtime_error("alias names are limited to alpha numeric words");
 
     auto it = std::find(colordesc.begin(), colordesc.end(), ',');
diff --git a/src/command_manager.cc b/src/command_manager.cc
index df23ca6e..b21921da 100644
--- a/src/command_manager.cc
+++ b/src/command_manager.cc
@@ -63,7 +63,7 @@ private:
 using TokenList = std::vector<Token>;
 using TokenPosList = std::vector<std::pair<CharCount, CharCount>>;
 
-bool is_command_separator(Character c)
+bool is_command_separator(char c)
 {
     return c == ';' or c == '\n';
 }
@@ -124,17 +124,17 @@ TokenList parse(const String& line,
             if (type_name == "opt")
                 type = Token::Type::OptionExpand;
 
-            static const std::unordered_map<Character, Character> matching_delimiters = {
+            static const std::unordered_map<char, char> matching_delimiters = {
                 { '(', ')' }, { '[', ']' }, { '{', '}' }, { '<', '>' }
             };
 
-            Character opening_delimiter = line[pos];
+            char opening_delimiter = line[pos];
             token_start = ++pos;
 
             auto delim_it = matching_delimiters.find(opening_delimiter);
             if (delim_it != matching_delimiters.end())
             {
-                Character closing_delimiter = delim_it->second;
+                char closing_delimiter = delim_it->second;
                 int level = 0;
                 while (pos != length)
                 {
diff --git a/src/keys.cc b/src/keys.cc
index b79c1940..696b704e 100644
--- a/src/keys.cc
+++ b/src/keys.cc
@@ -16,7 +16,7 @@ Key canonicalize_ifn(Key key)
     return key;
 }
 
-static std::unordered_map<String, Character> keynamemap = {
+static std::unordered_map<String, utf8::Codepoint> keynamemap = {
     { "ret", '\r' },
     { "space", ' ' },
     { "esc", Key::Escape }
@@ -53,7 +53,7 @@ KeyList parse_keys(const String& str)
                 }
                 if (keyname.length() == 1)
                 {
-                    result.push_back(Key{ modifier, keyname[0] });
+                    result.push_back(Key{ modifier, utf8::Codepoint(keyname[0]) });
                     pos = end_pos;
                     continue;
                 }
@@ -67,7 +67,7 @@ KeyList parse_keys(const String& str)
                 }
             }
         }
-        result.push_back({Key::Modifiers::None, str[pos]});
+        result.push_back({Key::Modifiers::None, utf8::Codepoint(str[pos])});
     }
     return result;
 }
diff --git a/src/keys.hh b/src/keys.hh
index 788a25bd..8355397f 100644
--- a/src/keys.hh
+++ b/src/keys.hh
@@ -2,6 +2,7 @@
 #define keys_hh_INCLUDED
 
 #include <vector>
+#include "utf8.hh"
 #include "string.hh"
 
 namespace Kakoune
@@ -16,9 +17,10 @@ struct Key
         Alt     = 2,
         ControlAlt = 3
     };
-    enum NamedKey : Character
+    enum NamedKey : utf8::Codepoint
     {
-        Backspace = 256,
+        // use UTF-16 surrogate pairs range
+        Backspace = 0xD800,
         Escape,
         Up,
         Down,
@@ -30,12 +32,12 @@ struct Key
     };
 
     Modifiers modifiers;
-    Character key;
+    utf8::Codepoint key;
 
-    constexpr Key(Modifiers modifiers, Character key)
+    constexpr Key(Modifiers modifiers, utf8::Codepoint key)
         : modifiers(modifiers), key(key) {}
 
-    constexpr Key(Character key)
+    constexpr Key(utf8::Codepoint key)
         : modifiers(Modifiers::None), key(key) {}
 
     constexpr bool operator==(const Key& other) const
diff --git a/src/ncurses.cc b/src/ncurses.cc
index a012fc67..9a916086 100644
--- a/src/ncurses.cc
+++ b/src/ncurses.cc
@@ -182,7 +182,7 @@ void NCursesUI::draw_window(Window& window)
 
 Key NCursesUI::get_key()
 {
-    const int c = getch();
+    const utf8::Codepoint c = getch();
 
     if (c > 0 and c < 27)
     {
@@ -191,7 +191,7 @@ Key NCursesUI::get_key()
     else if (c == 27)
     {
         timeout(0);
-        const int new_c = getch();
+        const utf8::Codepoint new_c = getch();
         timeout(-1);
         if (new_c != ERR)
             return {Key::Modifiers::Alt, new_c};
diff --git a/src/string.hh b/src/string.hh
index 31af1986..ad3a7b5f 100644
--- a/src/string.hh
+++ b/src/string.hh
@@ -11,7 +11,6 @@
 namespace Kakoune
 {
 
-typedef int32_t Character;
 typedef boost::regex Regex;
 
 class String
@@ -84,7 +83,7 @@ String int_to_str(int value);
 int    str_to_int(const String& str);
 std::vector<String> split(const String& str, char separator);
 
-inline bool is_word(Character c)
+inline bool is_word(char c)
 {
     return (c >= '0' and c <= '9') or
            (c >= 'a' and c <= 'z') or