diff --git a/plugins/input/topojson/topojson_datasource.cpp b/plugins/input/topojson/topojson_datasource.cpp
index 2cfad1fb8..67bae443b 100644
--- a/plugins/input/topojson/topojson_datasource.cpp
+++ b/plugins/input/topojson/topojson_datasource.cpp
@@ -160,7 +160,7 @@ topojson_datasource::topojson_datasource(parameters const& params)
     }
     if (!inline_string_.empty())
     {
-        parse_topojson(inline_string_);
+        parse_topojson(inline_string_.c_str());
     }
     else
     {
@@ -172,20 +172,22 @@ topojson_datasource::topojson_datasource(parameters const& params)
         std::string file_buffer;
         file_buffer.resize(file.size());
         std::fread(&file_buffer[0], file.size(), 1, file.get());
-        parse_topojson(file_buffer);
+        parse_topojson(file_buffer.c_str());
     }
 }
 
 namespace {
-using base_iterator_type = std::string::const_iterator;
-const mapnik::topojson::topojson_grammar<base_iterator_type> g;
+using iterator_type = const char*;
+const mapnik::topojson::topojson_grammar<iterator_type> g;
 }
 
 template <typename T>
 void topojson_datasource::parse_topojson(T const& buffer)
 {
     boost::spirit::standard::space_type space;
-    bool result = boost::spirit::qi::phrase_parse(buffer.begin(), buffer.end(), g, space, topo_);
+    auto itr = buffer;
+    auto end = buffer + std::strlen(buffer);
+    bool result = boost::spirit::qi::phrase_parse(itr, end, g, space, topo_);
     if (!result)
     {
         throw mapnik::datasource_exception("topojson_datasource: Failed parse TopoJSON file '" + filename_ + "'");
diff --git a/src/json/generic_json.cpp b/src/json/generic_json.cpp
index 92cd908b5..7fb2e9fd3 100644
--- a/src/json/generic_json.cpp
+++ b/src/json/generic_json.cpp
@@ -61,4 +61,3 @@ generic_json<Iterator>::generic_json()
 
 using iterator_type = char const*;
 template struct mapnik::json::generic_json<iterator_type>;
-template struct mapnik::json::generic_json<std::string::const_iterator>;
diff --git a/src/json/mapnik_topojson_grammar.cpp b/src/json/mapnik_topojson_grammar.cpp
index e70f7c590..e4b9dca32 100644
--- a/src/json/mapnik_topojson_grammar.cpp
+++ b/src/json/mapnik_topojson_grammar.cpp
@@ -24,5 +24,5 @@
 #include <mapnik/json/topojson_grammar_impl.hpp>
 #include <string>
 
-using iterator_type = std::string::const_iterator;
+using iterator_type = char const*;
 template struct mapnik::topojson::topojson_grammar<iterator_type> ;
diff --git a/test/unit/datasource/topojson.cpp b/test/unit/datasource/topojson.cpp
index 41d9b1908..7bf155e33 100644
--- a/test/unit/datasource/topojson.cpp
+++ b/test/unit/datasource/topojson.cpp
@@ -31,7 +31,7 @@
 
 namespace {
 
-using iterator_type = std::string::const_iterator;
+using iterator_type = char const*;
 const mapnik::topojson::topojson_grammar<iterator_type> grammar;
 
 bool parse_topology(std::string const& filename, mapnik::topojson::topology & topo)
@@ -42,8 +42,8 @@ bool parse_topology(std::string const& filename, mapnik::topojson::topology & to
     std::fread(&buffer[0], buffer.size(), 1, file.get());
     if (!file) return false;
     boost::spirit::standard::space_type space;
-    iterator_type itr = buffer.begin();
-    iterator_type end = buffer.end();
+    iterator_type itr = buffer.c_str();
+    iterator_type end = itr + buffer.length();
     bool result = boost::spirit::qi::phrase_parse(itr, end, grammar, space, topo);
     return (result && (itr == end));
 }