diff --git a/include/mapnik/image_filter_parser.hpp b/include/mapnik/image_filter_parser.hpp
index 91d4d6969..d860d0e61 100644
--- a/include/mapnik/image_filter_parser.hpp
+++ b/include/mapnik/image_filter_parser.hpp
@@ -52,7 +52,7 @@ struct image_filter_grammar :
 
 #if BOOST_VERSION >= 104700
         using qi::no_skip;
-        start = -(filter % no_skip[*char_("; ")])
+        start = -(filter % no_skip[*char_(", ")])
             ;
 #else
         start = -(filter)