diff --git a/test/visual/parse_map_sizes.cpp b/test/visual/parse_map_sizes.cpp
index 56df50e99..d0df2db9d 100644
--- a/test/visual/parse_map_sizes.cpp
+++ b/test/visual/parse_map_sizes.cpp
@@ -38,8 +38,9 @@ namespace visual_tests {
 
 namespace x3 = boost::spirit::x3;
 using x3::ulong_;
-auto const map_sizes_grammar = x3::rule<class map_sizes_grammar_type, std::vector<map_size> >{} =
-    (ulong_ >> ',' >> ulong_) % ';' ;
+auto const map_size_rule = x3::rule<class map_size_rule, map_size> {} = ulong_ >> ',' >> ulong_;
+auto const map_sizes_grammar = x3::rule<class map_sizes_grammar_type, std::vector<map_size> > {} =
+    map_size_rule  % ';' ;
 
 void parse_map_sizes(std::string const & str, std::vector<map_size> & sizes)
 {