diff --git a/src/commands.cc b/src/commands.cc
index 386a71814..6dbe59f2a 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -267,8 +267,7 @@ void add_highlighter(CommandParameters params, Context& context)
         get_group(window.highlighters(), parser.option_value("group"))
       : window.highlighters();
 
-    auto& factory = registry[name];
-    group.append(factory(highlighter_params, window));
+    group.append(registry[name](highlighter_params));
 }
 
 void rm_highlighter(CommandParameters params, Context& context)
diff --git a/src/highlighter.hh b/src/highlighter.hh
index e3561bee0..a81d98170 100644
--- a/src/highlighter.hh
+++ b/src/highlighter.hh
@@ -24,8 +24,7 @@ typedef std::function<void (const Window& window, DisplayBuffer& display_buffer)
 typedef std::pair<String, HighlighterFunc> HighlighterAndId;
 typedef memoryview<String> HighlighterParameters;
 
-using HighlighterFactory = std::function<HighlighterAndId (HighlighterParameters params,
-                                                           Window& window)>;
+using HighlighterFactory = std::function<HighlighterAndId (HighlighterParameters params)>;
 
 using HighlighterGroup = FunctionGroup<const Window&, DisplayBuffer&>;
 
diff --git a/src/highlighters.cc b/src/highlighters.cc
index af9d04d30..db4a2b277 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -128,7 +128,7 @@ private:
     }
 };
 
-HighlighterAndId colorize_regex_factory(HighlighterParameters params, const Window&)
+HighlighterAndId colorize_regex_factory(HighlighterParameters params)
 {
     if (params.size() < 2)
         throw runtime_error("wrong parameter count");
@@ -190,7 +190,7 @@ private:
     RegexGetter    m_regex_getter;
 };
 
-HighlighterAndId highlight_search_factory(HighlighterParameters params, const Window&)
+HighlighterAndId highlight_search_factory(HighlighterParameters params)
 {
     if (params.size() != 1)
         throw runtime_error("wrong parameter count");
@@ -209,7 +209,7 @@ HighlighterAndId highlight_search_factory(HighlighterParameters params, const Wi
     }
 }
 
-HighlighterAndId highlight_regex_option_factory(HighlighterParameters params, const Window&)
+HighlighterAndId highlight_regex_option_factory(HighlighterParameters params)
 {
     if (params.size() != 2)
         throw runtime_error("wrong parameter count");
@@ -345,7 +345,7 @@ void expand_unprintable(const Window& window, DisplayBuffer& display_buffer)
     }
 }
 
-HighlighterAndId flag_lines_factory(HighlighterParameters params, Window& window)
+HighlighterAndId flag_lines_factory(HighlighterParameters params)
 {
     if (params.size() != 2)
         throw runtime_error("wrong parameter count");
@@ -387,7 +387,7 @@ class SimpleHighlighterFactory
 public:
     SimpleHighlighterFactory(const String& id) : m_id(id) {}
 
-    HighlighterAndId operator()(HighlighterParameters params, const Window&) const
+    HighlighterAndId operator()(HighlighterParameters params) const
     {
         return HighlighterAndId(m_id, HighlighterFunc(highlighter_func));
     }
@@ -395,7 +395,7 @@ private:
     String m_id;
 };
 
-HighlighterAndId highlighter_group_factory(HighlighterParameters params, const Window&)
+HighlighterAndId highlighter_group_factory(HighlighterParameters params)
 {
     if (params.size() != 1)
         throw runtime_error("wrong parameter count");