diff --git a/include/mapnik/symbolizer.hpp b/include/mapnik/symbolizer.hpp
index e7eda7649..2e72349b0 100644
--- a/include/mapnik/symbolizer.hpp
+++ b/include/mapnik/symbolizer.hpp
@@ -381,7 +381,6 @@ struct extract_value : public boost::static_visitor<T>
 
     auto operator() (result_type const& val) const -> result_type
     {
-        boost::ignore_unused_variable_warning(val);
         return val;
     }