diff --git a/src/command_manager.cc b/src/command_manager.cc
index 267dc44e..1a55a957 100644
--- a/src/command_manager.cc
+++ b/src/command_manager.cc
@@ -267,7 +267,7 @@ void CommandManager::execute(const String& command_line,
         if (it->type() == Token::Type::OptionExpand)
         {
             const Option& option = context.options()[it->content()];
-            params.push_back(option.as_string());
+            params.push_back(option.get_as_string());
         }
         if (it->type() == Token::Type::CommandSeparator)
         {
diff --git a/src/commands.cc b/src/commands.cc
index e143acca..6dce3986 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -466,7 +466,24 @@ void set_option(OptionManager& options, const CommandParameters& params,
     if (params.size() != 2)
         throw wrong_argument_count();
 
-    options.set_option(params[0], Option(params[1]));
+    options.get_local_option(params[0]).set_from_string(params[1]);
+}
+
+void declare_option(const CommandParameters& params, Context& context)
+{
+    if (params.size() != 2 and params.size() != 3)
+        throw wrong_argument_count();
+    Option* opt = nullptr;
+
+    if (params[0] == "int")
+        opt = &GlobalOptions::instance().declare_option<int>(params[1], 0);
+    else if (params[0] == "str")
+        opt = &GlobalOptions::instance().declare_option<String>(params[1], "");
+    else
+        throw runtime_error("unknown type " + params[0]);
+
+    if (params.size() == 3)
+        opt->set_from_string(params[2]);
 }
 
 template<typename Func>
@@ -878,6 +895,7 @@ void register_commands()
                              [](const Context& context, const String& prefix, ByteCount cursor_pos)
                              { return context.window().options().complete_option_name(prefix, cursor_pos); }
                          }));
+    cm.register_command("decl", declare_option);
 
     cm.register_commands({"ca", "colalias"}, define_color_alias);
     cm.register_commands({"name"}, set_client_name);
diff --git a/src/completion.cc b/src/completion.cc
index 2c7cea11..ad66ee3c 100644
--- a/src/completion.cc
+++ b/src/completion.cc
@@ -36,7 +36,7 @@ CandidateList complete_filename(const Context& context,
     String dirprefix;
     String fileprefix = real_prefix;
 
-    boost::regex ignored_files = make_regex_ifp(context.options()["ignored_files"].as_string());
+    boost::regex ignored_files = make_regex_ifp(context.options()["ignored_files"].get<String>());
 
     ByteCount dir_end = -1;
     for (ByteCount i = 0; i < real_prefix.length(); ++i)
diff --git a/src/file.cc b/src/file.cc
index 6d184349..c2b8c170 100644
--- a/src/file.cc
+++ b/src/file.cc
@@ -135,8 +135,8 @@ Buffer* create_buffer_from_file(const String& filename)
     Buffer* buffer = new Buffer(filename, Buffer::Flags::File, std::move(lines));
 
     OptionManager& options = buffer->options();
-    options.set_option("eolformat", Option(crlf ? "crlf" : "lf"));
-    options.set_option("BOM", Option(bom ? "utf-8" : "no"));
+    options.get_local_option("eolformat").set<String>(crlf ? "crlf" : "lf");
+    options.get_local_option("BOM").set<String>(bom ? "utf-8" : "no");
 
     return buffer;
 }
@@ -159,7 +159,7 @@ static void write(int fd, const memoryview<char>& data, const String& filename)
 
 void write_buffer_to_file(const Buffer& buffer, const String& filename)
 {
-    String eolformat = buffer.options()["eolformat"].as_string();
+    String eolformat = buffer.options()["eolformat"].get<String>();
     if (eolformat == "crlf")
         eolformat = "\r\n";
     else
@@ -172,7 +172,7 @@ void write_buffer_to_file(const Buffer& buffer, const String& filename)
         throw file_access_error(filename, strerror(errno));
     auto close_fd = on_scope_end([fd]{ close(fd); });
 
-    if (buffer.options()["BOM"].as_string() == "utf-8")
+    if (buffer.options()["BOM"].get<String>() == "utf-8")
         ::write(fd, "\xEF\xBB\xBF", 3);
 
     for (LineCount i = 0; i < buffer.line_count(); ++i)
diff --git a/src/filters.cc b/src/filters.cc
index 267144a9..238de5e0 100644
--- a/src/filters.cc
+++ b/src/filters.cc
@@ -37,7 +37,7 @@ void cleanup_whitespaces(Buffer& buffer, Selection& selection, String& content)
 
 void expand_tabulations(Buffer& buffer, Selection& selection, String& content)
 {
-    const int tabstop = buffer.options()["tabstop"].as_int();
+    const int tabstop = buffer.options()["tabstop"].get<int>();
     if (content == "\t")
     {
         int column = 0;
diff --git a/src/highlighters.cc b/src/highlighters.cc
index b406ab08..3afd50ce 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -200,7 +200,7 @@ HighlighterAndId highlight_search_factory(const HighlighterParameters params)
 
 void expand_tabulations(const OptionManager& options, DisplayBuffer& display_buffer)
 {
-    const int tabstop = options["tabstop"].as_int();
+    const int tabstop = options["tabstop"].get<int>();
     for (auto& line : display_buffer.lines())
     {
         for (auto atom_it = line.begin(); atom_it != line.end(); ++atom_it)
diff --git a/src/input_handler.cc b/src/input_handler.cc
index 663a924d..16454499 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -377,7 +377,7 @@ public:
                 DisplayCoord menu_pos{ context().ui().dimensions().line, 0_char };
                 context().ui().menu_show(candidates, menu_pos, MenuStyle::Prompt);
 
-                bool use_common_prefix = context().options()["complete_prefix"].as_int();
+                bool use_common_prefix = context().options()["complete_prefix"].get<int>();
                 String prefix = use_common_prefix ? common_prefix(candidates) : String();
                 if (m_completions.end - m_completions.start > prefix.length())
                     prefix = line.substr(m_completions.start,
diff --git a/src/main.cc b/src/main.cc
index 0bc2603e..2e8692bd 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -176,7 +176,7 @@ void do_search(Context& context)
                         RegisterManager::instance()['/'] = ex;
                     context.push_jump();
                 }
-                else if (ex.empty() or not context.options()["incsearch"].as_int())
+                else if (ex.empty() or not context.options()["incsearch"].get<int>())
                     return;
 
                 context.editor().select(std::bind(select_next_match<forward>, _1, ex), mode);
@@ -338,7 +338,7 @@ void do_join(Context& context)
 
 void do_indent(Context& context)
 {
-    size_t width = context.options()["indentwidth"].as_int();
+    size_t width = context.options()["indentwidth"].get<int>();
     String indent(' ', width);
 
     Editor& editor = context.editor();
@@ -351,7 +351,7 @@ void do_indent(Context& context)
 
 void do_deindent(Context& context)
 {
-    int width = context.options()["indentwidth"].as_int();
+    int width = context.options()["indentwidth"].get<int>();
     Editor& editor = context.editor();
     DynamicSelectionList sels{editor.buffer(), editor.selections()};
     auto restore_sels = on_scope_end([&]{ editor.select((SelectionList)std::move(sels)); });
@@ -745,7 +745,7 @@ void register_env_vars()
                                    { return runtime_directory(); });
     shell_manager.register_env_var("opt_.+",
                                    [](const String& name, const Context& context)
-                                   { return context.options()[name.substr(4_byte)].as_string(); });
+                                   { return context.options()[name.substr(4_byte)].get_as_string(); });
     shell_manager.register_env_var("reg_.+",
                                    [](const String& name, const Context& context)
                                    { return RegisterManager::instance()[name[4]].values(context)[0]; });
diff --git a/src/option_manager.cc b/src/option_manager.cc
index 3857c78e..f08a23e9 100644
--- a/src/option_manager.cc
+++ b/src/option_manager.cc
@@ -6,6 +6,54 @@
 namespace Kakoune
 {
 
+template<typename T>
+class TypedOption : public Option
+{
+public:
+    TypedOption(OptionManager& manager, String name, const T& value)
+        : Option(manager, std::move(name)), m_value(value) {}
+
+    void set(const T& value)
+    {
+        if (m_value != value)
+        {
+            m_value = value;
+            m_manager.on_option_changed(*this);
+        }
+    }
+    const T& get() const { return m_value; }
+
+    String get_as_string() const override;
+    void   set_from_string(const String& str) override;
+
+    Option* clone(OptionManager& manager) const override
+    {
+        return new TypedOption{manager, name(), m_value};
+    }
+private:
+    T m_value;
+};
+
+Option::Option(OptionManager& manager, String name)
+    : m_manager(manager), m_name(std::move(name)) {}
+
+template<typename T> const T& Option::get() const { return dynamic_cast<const TypedOption<T>*>(this)->get(); }
+template<typename T> void     Option::set(const T& val) { return dynamic_cast<TypedOption<T>*>(this)->set(val); }
+
+// TypedOption<String> specializations;
+template<> String TypedOption<String>::get_as_string() const { return m_value; }
+template<> void   TypedOption<String>::set_from_string(const String& str) { set(str); }
+template class TypedOption<String>;
+template const String& Option::get<String>() const;
+template void Option::set<String>(const String&);
+
+// TypedOption<int> specializations;
+template<> String TypedOption<int>::get_as_string() const { return int_to_str(m_value); }
+template<> void   TypedOption<int>::set_from_string(const String& str) { set(str_to_int(str)); }
+template class TypedOption<int>;
+template const int& Option::get<int>() const;
+template void Option::set<int>(const int&);
+
 OptionManager::OptionManager(OptionManager& parent)
     : m_parent(&parent)
 {
@@ -33,23 +81,33 @@ void OptionManager::unregister_watcher(OptionManagerWatcher& watcher)
     m_watchers.erase(it);
 }
 
-void OptionManager::set_option(const String& name, const Option& value)
+template<typename T>
+auto find_option(T& container, const String& name) -> decltype(container.begin())
 {
-    Option old_value = m_options[name];
-    m_options[name] = value;
+    using ptr_type = decltype(*container.begin());
+    return find_if(container, [&name](const ptr_type& opt) { return opt->name() == name; });
+}
 
-    if (old_value != value)
+Option& OptionManager::get_local_option(const String& name)
+{
+    auto it = find_option(m_options, name);
+    if (it != m_options.end())
+        return **it;
+    else if (m_parent)
     {
-        for (auto watcher : m_watchers)
-            watcher->on_option_changed(name, value);
+        m_options.emplace_back((*m_parent)[name].clone(*this));
+        return *m_options.back();
     }
+    else
+        throw option_not_found(name);
+
 }
 
 const Option& OptionManager::operator[](const String& name) const
 {
-    auto it = m_options.find(name);
+    auto it = find_option(m_options, name);
     if (it != m_options.end())
-        return it->second;
+        return **it;
     else if (m_parent)
         return (*m_parent)[name];
     else
@@ -65,42 +123,60 @@ CandidateList OptionManager::complete_option_name(const String& prefix,
         result = m_parent->complete_option_name(prefix, cursor_pos);
     for (auto& option : m_options)
     {
-        if (option.first.substr(0, real_prefix.length()) == real_prefix and
-            not contains(result, option.first))
-            result.push_back(option.first);
+        const auto& name = option->name();
+        if (name.substr(0, real_prefix.length()) == real_prefix and
+            not contains(result, name))
+            result.push_back(name);
     }
     return result;
 }
 
-OptionManager::OptionMap OptionManager::flatten_options() const
+OptionManager::OptionList OptionManager::flatten_options() const
 {
-    OptionMap res = m_parent ? m_parent->flatten_options() : OptionMap();
+    OptionList res = m_parent ? m_parent->flatten_options() : OptionList{};
     for (auto& option : m_options)
-        res.insert(option);
+    {
+        auto it = find_option(res, option->name());
+        if (it != res.end())
+            *it = option.get();
+        else
+            res.emplace_back(option.get());
+    }
     return res;
 }
 
-void OptionManager::on_option_changed(const String& name, const Option& value)
+void OptionManager::on_option_changed(const Option& option)
 {
     // if parent option changed, but we overrided it, it's like nothing happened
-    if (m_options.find(name) != m_options.end())
+    if (&option.manager() != this and
+        find_option(m_options, option.name()) != m_options.end())
         return;
 
     for (auto watcher : m_watchers)
-        watcher->on_option_changed(name, value);
+        watcher->on_option_changed(option);
 }
 
 GlobalOptions::GlobalOptions()
     : OptionManager()
 {
-    set_option("tabstop", Option(8));
-    set_option("indentwidth", Option(4));
-    set_option("eolformat", Option("lf"));
-    set_option("BOM", Option("no"));
-    set_option("shell", Option("sh"));
-    set_option("complete_prefix", Option(1));
-    set_option("incsearch", Option(1));
-    set_option("ignored_files", Option(R"(^(\..*|.*\.(o|so|a))$)"));
+    declare_option<int>("tabstop", 8);
+    declare_option<int>("indentwidth", 4);
+    declare_option<String>("eolformat", "lf");
+    declare_option<String>("BOM", "no");
+    declare_option<String>("shell", "sh");
+    declare_option<int>("complete_prefix", 1);
+    declare_option<int>("incsearch", 1);
+    declare_option<String>("ignored_files", R"(^(\..*|.*\.(o|so|a)))$)");
+    declare_option<String>("filetype", "");
+}
+
+template<typename T>
+Option& GlobalOptions::declare_option(const String& name, const T& value)
+{
+    if (find_option(m_options, name) != m_options.end())
+        throw runtime_error("option " + name + " already declared");
+    m_options.emplace_back(new TypedOption<T>{*this, name, value});
+    return *m_options.back();
 }
 
 }
diff --git a/src/option_manager.hh b/src/option_manager.hh
index 7b7f81c8..80443323 100644
--- a/src/option_manager.hh
+++ b/src/option_manager.hh
@@ -16,23 +16,27 @@ struct option_not_found : public runtime_error
         : runtime_error("option not found: " + name) {}
 };
 
+class OptionManager;
+
 class Option
 {
 public:
-    Option() {}
-    explicit Option(int value) : m_value(int_to_str(value)) {}
-    explicit Option(const String& value) : m_value(value) {}
+    Option(OptionManager& manager, String name);
+    virtual ~Option() {}
 
-    Option& operator=(int value) { m_value = int_to_str(value); return *this; }
-    Option& operator=(const String& value) { m_value = value; return *this; }
+    template<typename T> const T& get() const;
+    template<typename T> void set(const T& val);
 
-    bool operator==(const Option& other) const { return m_value == other.m_value; }
-    bool operator!=(const Option& other) const { return m_value != other.m_value; }
+    virtual String get_as_string() const = 0;
+    virtual void   set_from_string(const String& str) = 0;
 
-    int    as_int()    const  { return str_to_int(m_value); }
-    String as_string() const { return m_value; }
-private:
-    String m_value;
+    String name() const { return m_name; }
+    OptionManager& manager() const { return m_manager; }
+
+    virtual Option* clone(OptionManager& manager) const = 0;
+protected:
+    OptionManager& m_manager;
+    String m_name;
 };
 
 class OptionManagerWatcher
@@ -40,8 +44,7 @@ class OptionManagerWatcher
 public:
     virtual ~OptionManagerWatcher() {}
 
-    virtual void on_option_changed(const String& name,
-                                   const Option& option) = 0;
+    virtual void on_option_changed(const Option& option) = 0;
 };
 
 class OptionManager : private OptionManagerWatcher
@@ -51,29 +54,27 @@ public:
     ~OptionManager();
 
     const Option& operator[] (const String& name) const;
-
-    void set_option(const String& name, const Option& value);
+    Option& get_local_option(const String& name);
 
     CandidateList complete_option_name(const String& prefix,
                                        ByteCount cursor_pos);
 
-    typedef std::unordered_map<String, Option> OptionMap;
-    OptionMap flatten_options() const;
+    using OptionList = std::vector<const Option*>;
+    OptionList flatten_options() const;
 
     void register_watcher(OptionManagerWatcher& watcher);
     void unregister_watcher(OptionManagerWatcher& watcher);
 
+    void on_option_changed(const Option& option) override;
 private:
     OptionManager()
         : m_parent(nullptr) {}
     // the only one allowed to construct a root option manager
     friend class GlobalOptions;
 
-    OptionMap m_options;
+    std::vector<std::unique_ptr<Option>> m_options;
     OptionManager* m_parent;
 
-    void on_option_changed(const String& name, const Option& value);
-
     std::vector<OptionManagerWatcher*> m_watchers;
 };
 
@@ -82,8 +83,10 @@ class GlobalOptions : public OptionManager,
 {
 public:
     GlobalOptions();
-};
 
+    template<typename T>
+    Option& declare_option(const String& name, const T& inital_value);
+};
 
 }
 
diff --git a/src/rc/client.kak b/src/rc/client.kak
index 6bb0cd05..234c8353 100644
--- a/src/rc/client.kak
+++ b/src/rc/client.kak
@@ -1,4 +1,4 @@
-setg termcmd %sh{
+decl str termcmd %sh{
     if [[ -n "$TMUX" ]]; then
         echo "'tmux split-window -h'"
     else
diff --git a/src/rc/grep.kak b/src/rc/grep.kak
index b050f862..53e2c2df 100644
--- a/src/rc/grep.kak
+++ b/src/rc/grep.kak
@@ -1,4 +1,4 @@
-setg grepcmd 'grep -RHn'
+decl str grepcmd 'grep -RHn'
 
 def -shell-params -file-completion \
     grep %{ %sh{
diff --git a/src/rc/make.kak b/src/rc/make.kak
index a2a6d10f..269ef10b 100644
--- a/src/rc/make.kak
+++ b/src/rc/make.kak
@@ -1,4 +1,4 @@
-setg makecmd make
+decl str makecmd make
 
 def -shell-params make %{ %sh{
      output=$(mktemp -d -t kak-make.XXXXXXXX)/fifo
diff --git a/src/shell_manager.cc b/src/shell_manager.cc
index 31a9d4c2..31ff0b1b 100644
--- a/src/shell_manager.cc
+++ b/src/shell_manager.cc
@@ -119,7 +119,7 @@ String ShellManager::pipe(const String& input,
 
             ++it;
         }
-        String shell = context.options()["shell"].as_string();
+        String shell = context.options()["shell"].get<String>();
         std::vector<const char*> execparams = { shell.c_str(), "-c", cmdline.c_str() };
         if (not params.empty())
             execparams.push_back(shell.c_str());
diff --git a/src/window.cc b/src/window.cc
index e38900a7..473fa5f5 100644
--- a/src/window.cc
+++ b/src/window.cc
@@ -30,7 +30,7 @@ Window::Window(Buffer& buffer)
     m_builtin_highlighters.append({"selections",  [this](DisplayBuffer& db) { highlight_selections(selections(), db); }});
 
     for (auto& option : m_options.flatten_options())
-        on_option_changed(option.first, option.second);
+        on_option_changed(*option);
 }
 
 Window::~Window()
@@ -177,9 +177,9 @@ DisplayCoord Window::display_position(const BufferIterator& iterator)
     return { 0, 0 };
 }
 
-void Window::on_option_changed(const String& name, const Option& option)
+void Window::on_option_changed(const Option& option)
 {
-    String desc = name + "=" + option.as_string();
+    String desc = option.name() + "=" + option.get_as_string();
     Context hook_context{*this};
     m_hooks.run_hook("WinSetOption", desc, hook_context);
 }
diff --git a/src/window.hh b/src/window.hh
index 9c62356f..68276422 100644
--- a/src/window.hh
+++ b/src/window.hh
@@ -51,7 +51,7 @@ public:
 private:
     Window(const Window&) = delete;
 
-    void on_option_changed(const String& name, const Option& option) override;
+    void on_option_changed(const Option& option) override;
 
     void scroll_to_keep_cursor_visible_ifn();