diff --git a/src/commands.cc b/src/commands.cc
index 51e917f51..82d30840d 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -446,7 +446,7 @@ Completions add_highlighter_completer(
     if (token_to_complete == 1 and params[0] == "-group")
         return complete_highlighter(context, params[1], pos_in_token, true);
     else if (token_to_complete == 0 or (token_to_complete == 2 and params[0] == "-group"))
-        return { 0_byte, arg.length(), HighlighterRegistry::instance().complete_name(arg, pos_in_token) };
+        return { 0_byte, arg.length(), complete(arg, pos_in_token, transformed(HighlighterRegistry::instance(), HighlighterRegistry::get_id)) };
     return Completions{};
 }
 
@@ -495,7 +495,10 @@ const CommandDesc add_highlighter_cmd = {
         auto& group = (parser.has_option("group")) ?
             get_highlighter(context, parser.option_value("group"))
           : context.window().highlighters();
-        group.add_child(registry[name](highlighter_params));
+        auto it = registry.find(name);
+        if (it == registry.end())
+            throw runtime_error("No such highlighter factory '" + name + "'");
+        group.add_child(it->second(highlighter_params));
     }
 };
 
diff --git a/src/function_registry.hh b/src/function_registry.hh
deleted file mode 100644
index cf0ea46e5..000000000
--- a/src/function_registry.hh
+++ /dev/null
@@ -1,49 +0,0 @@
-#ifndef function_registry_h_INCLUDED
-#define function_registry_h_INCLUDED
-
-#include "completion.hh"
-#include "id_map.hh"
-#include "string.hh"
-#include "exception.hh"
-#include "containers.hh"
-
-namespace Kakoune
-{
-
-struct function_not_found : runtime_error
-{
-    function_not_found(StringView name)
-        : runtime_error("'" + name + "' not found") {}
-};
-
-template<typename FunctionType>
-class FunctionRegistry
-{
-public:
-    void register_func(StringView name, const FunctionType& function)
-    {
-        kak_assert(not m_functions.contains(name));
-        m_functions.append(std::make_pair(name, function));
-    }
-
-    const FunctionType& operator[](StringView name) const
-    {
-        auto it = m_functions.find(name);
-        if (it == m_functions.end())
-            throw function_not_found(name);
-        return it->second;
-    }
-
-    CandidateList complete_name(StringView prefix, ByteCount cursor_pos)
-    {
-        auto c = transformed(m_functions, id_map<FunctionType>::get_id);
-        return complete(prefix, cursor_pos, c);
-    }
-
-private:
-    id_map<FunctionType> m_functions;
-};
-
-}
-
-#endif // function_registry_h_INCLUDED
diff --git a/src/highlighter.hh b/src/highlighter.hh
index bf67cbcb9..7d7f5a1d3 100644
--- a/src/highlighter.hh
+++ b/src/highlighter.hh
@@ -2,7 +2,9 @@
 #define highlighter_hh_INCLUDED
 
 #include "coord.hh"
-#include "function_registry.hh"
+#include "completion.hh"
+#include "exception.hh"
+#include "id_map.hh"
 #include "memoryview.hh"
 #include "string.hh"
 #include "utils.hh"
@@ -65,7 +67,7 @@ std::unique_ptr<SimpleHighlighter<T>> make_simple_highlighter(T func)
 using HighlighterParameters = memoryview<String>;
 using HighlighterFactory = std::function<HighlighterAndId (HighlighterParameters params)>;
 
-struct HighlighterRegistry : FunctionRegistry<HighlighterFactory>,
+struct HighlighterRegistry : id_map<HighlighterFactory>,
                              Singleton<HighlighterRegistry>
 {};
 
diff --git a/src/highlighters.cc b/src/highlighters.cc
index a60f70f39..cb4eb7c37 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -1122,18 +1122,18 @@ void register_highlighters()
 {
     HighlighterRegistry& registry = HighlighterRegistry::instance();
 
-    registry.register_func("number_lines", simple_factory("number_lines", show_line_numbers));
-    registry.register_func("show_matching", simple_factory("show_matching", show_matching_char));
-    registry.register_func("show_whitespaces", simple_factory("show_whitespaces", show_whitespaces));
-    registry.register_func("fill", create_fill_highlighter);
-    registry.register_func("regex", RegexHighlighter::create);
-    registry.register_func("regex_option", create_regex_option_highlighter);
-    registry.register_func("search", create_search_highlighter);
-    registry.register_func("group", create_highlighter_group);
-    registry.register_func("flag_lines", create_flag_lines_highlighter);
-    registry.register_func("line_option", create_line_option_highlighter);
-    registry.register_func("ref", create_reference_highlighter);
-    registry.register_func("regions", RegionsHighlighter::create);
+    registry.append({ "number_lines", simple_factory("number_lines", show_line_numbers) });
+    registry.append({ "show_matching", simple_factory("show_matching", show_matching_char) });
+    registry.append({ "show_whitespaces", simple_factory("show_whitespaces", show_whitespaces) });
+    registry.append({ "fill", create_fill_highlighter });
+    registry.append({ "regex", RegexHighlighter::create });
+    registry.append({ "regex_option", create_regex_option_highlighter });
+    registry.append({ "search", create_search_highlighter });
+    registry.append({ "group", create_highlighter_group });
+    registry.append({ "flag_lines", create_flag_lines_highlighter });
+    registry.append({ "line_option", create_line_option_highlighter });
+    registry.append({ "ref", create_reference_highlighter });
+    registry.append({ "regions", RegionsHighlighter::create });
 }
 
 }