diff --git a/include/mapnik/expression_grammar_x3_def.hpp b/include/mapnik/expression_grammar_x3_def.hpp
index 23735e5de..2b5f24236 100644
--- a/include/mapnik/expression_grammar_x3_def.hpp
+++ b/include/mapnik/expression_grammar_x3_def.hpp
@@ -24,6 +24,7 @@
 #define MAPNIK_EXPRESSIONS_GRAMMAR_X3_DEF_HPP
 
 #include <mapnik/expression_grammar_x3.hpp>
+#include <mapnik/json/unicode_string_grammar_x3_def.hpp>
 #include <mapnik/expression_node.hpp>
 #include <mapnik/function_call.hpp>
 #include <mapnik/unicode.hpp>
@@ -65,6 +66,9 @@ namespace mapnik { namespace grammar {
     using x3::alnum;
     x3::uint_parser<char, 16, 2, 2> const hex2 {};
 
+    namespace {
+    auto const& double_quoted = json::unicode_string_grammar();
+    }
     auto do_assign = [] (auto const& ctx)
     {
         _val(ctx) = std::move(_attr(ctx));
@@ -303,8 +307,8 @@ namespace mapnik { namespace grammar {
 
     // strings
     auto const single_quoted_string = x3::rule<class single_quoted_string, std::string> {} = lit('\'') >> no_skip[*(unesc_char | ("\\x" > hex2) | (char_ - '\''))] > '\'';
-    auto const double_quoted_string = x3::rule<class double_quoted_string, std::string> {} = lit('"') >> no_skip[*(unesc_char | ("\\x" > hex2) | (char_ - '"'))] > '"';
-    auto const quoted_string = x3::rule<class quoted_string, std::string> {} = single_quoted_string | double_quoted_string;
+    //auto const double_quoted_string = x3::rule<class double_quoted_string, std::string> {} = lit('"') >> no_skip[*(unesc_char | ("\\x" > hex2) | (char_ - '"'))] > '"';
+    auto const quoted_string = x3::rule<class quoted_string, std::string> {} = single_quoted_string | double_quoted;//_string;
 
     auto const unquoted_ustring = x3::rule<class ustring, std::string> {} = no_skip[alpha > *alnum] - lit("not");