diff --git a/include/mapnik/json/feature_grammar_x3_def.hpp b/include/mapnik/json/feature_grammar_x3_def.hpp
index d2a4ad57f..1e18faeec 100644
--- a/include/mapnik/json/feature_grammar_x3_def.hpp
+++ b/include/mapnik/json/feature_grammar_x3_def.hpp
@@ -273,7 +273,7 @@ auto const feature_part_def = feature_type
     |
     (lit("\"properties\"") > lit(':') > lit('{') > -properties > lit('}'))
     |
-    omit[geojson_string] > lit(':') > omit[value]
+    (omit[geojson_string] > lit(':') > omit[value])
     ;
 
 
diff --git a/include/mapnik/json/unicode_string_grammar_x3_def.hpp b/include/mapnik/json/unicode_string_grammar_x3_def.hpp
index 1e3d0094e..d58293cf3 100644
--- a/include/mapnik/json/unicode_string_grammar_x3_def.hpp
+++ b/include/mapnik/json/unicode_string_grammar_x3_def.hpp
@@ -95,11 +95,11 @@ x3::rule<class escaped_tag, std::string> const escaped("Escaped Characted");
 auto unicode_string_def = double_quoted
     ;
 auto const escaped_def = lit('\\') >
-    (lit('x') > hex[push_utf8]
+    ((lit('x') > hex[push_utf8])
      |
-     lit('u') > hex4[push_utf8]
+     (lit('u') > hex4[push_utf8])
      |
-     lit('U') > hex8[push_utf8]
+     (lit('U') > hex8[push_utf8])
      |
      char_("0abtnvfre\"/\\N_LP \t")[push_esc]
      |
diff --git a/src/json/extract_bounding_boxes_x3.cpp b/src/json/extract_bounding_boxes_x3.cpp
index 7aadea8e5..a744c7eff 100644
--- a/src/json/extract_bounding_boxes_x3.cpp
+++ b/src/json/extract_bounding_boxes_x3.cpp
@@ -41,29 +41,29 @@ struct calculate_bounding_box
         box_.init(pt.x, pt.y);
     }
 
-    void operator()(mapnik::json::ring const& ring) const
+    void operator()(mapnik::json::ring const& r) const
     {
-        for (auto const& pt : ring)
+        for (auto const& pt : r)
         {
             if (!box_.valid()) box_.init(pt.x, pt.y);
             else box_.expand_to_include(pt.x, pt.y);
         }
     }
 
-    void operator()(mapnik::json::rings const& rings) const
+    void operator()(mapnik::json::rings const& rs) const
     {
-        for (auto const& ring : rings)
+        for (auto const& r : rs)
         {
-            operator()(ring);
+            operator()(r);
             break; // consider first ring only
         }
     }
 
-    void operator()(mapnik::json::rings_array const& rings_array) const
+    void operator()(mapnik::json::rings_array const& rings_ar) const
     {
-        for (auto const& rings : rings_array)
+        for (auto const& rs : rings_ar)
         {
-            operator()(rings);
+            operator()(rs);
         }
     }
 
@@ -142,18 +142,19 @@ x3::rule<struct feature_collection_tag> const feature_collection = "Feature Coll
 
 auto const coordinates_rule_def = lit("\"coordinates\"") >> lit(':') >> positions_rule[extract_bounding_box];
 
-auto const bounding_box_def = raw[lit('{')[open_bracket] >> *(eps[check_brackets] >>
-                                  (lit("\"FeatureCollection\"") > eps(false)
-                                   |
-                                   lit('{')[open_bracket]
-                                   |
-                                   lit('}')[close_bracket]
-                                   |
-                                   coordinates_rule[assign_bbox]
-                                   |
-                                   omit[geojson_string]
-                                   |
-                                   omit[char_]))][assign_range];
+auto const bounding_box_def = raw[lit('{')[open_bracket]
+                                  >> *(eps[check_brackets] >>
+                                       ((lit("\"FeatureCollection\"") > eps(false))
+                                        |
+                                        lit('{')[open_bracket]
+                                        |
+                                        lit('}')[close_bracket]
+                                        |
+                                        coordinates_rule[assign_bbox]
+                                        |
+                                        omit[geojson_string]
+                                        |
+                                        omit[char_]))][assign_range];
 
 
 auto const feature = bounding_box[on_feature_callback];