diff --git a/src/mapnik_memory_datasource.cpp b/src/mapnik_memory_datasource.cpp
index d8765ffb97..090ecbff86 100644
--- a/src/mapnik_memory_datasource.cpp
+++ b/src/mapnik_memory_datasource.cpp
@@ -35,7 +35,7 @@ void MemoryDatasource::Initialize(Handle<Object> target) {
 MemoryDatasource::MemoryDatasource() :
   ObjectWrap(),
   datasource_(),
-  count_(0),
+  feature_id_(1),
   tr_(new mapnik::transcoder("utf8")) {}
 
 MemoryDatasource::~MemoryDatasource()
@@ -232,7 +232,8 @@ Handle<Value> MemoryDatasource::add(const Arguments& args)
         {
             mapnik::geometry_type * pt = new mapnik::geometry_type(mapnik::Point);
             pt->move_to(x->NumberValue(),y->NumberValue());
-            mapnik::feature_ptr feature(new mapnik::Feature(d->count_));
+            mapnik::feature_ptr feature(new mapnik::Feature(d->feature_id_));
+            ++(d->feature_id_);
             feature->add_geometry(pt);
             if (obj->Has(String::New("properties")))
             {
@@ -270,7 +271,6 @@ Handle<Value> MemoryDatasource::add(const Arguments& args)
             }
             mapnik::memory_datasource *cache = dynamic_cast<mapnik::memory_datasource *>(d->datasource_.get());
             cache->push(feature);
-            ++(d->count_);
         }
     }
     return scope.Close(Boolean::New(false));
diff --git a/src/mapnik_memory_datasource.hpp b/src/mapnik_memory_datasource.hpp
index 3dcfab356d..845d70517b 100644
--- a/src/mapnik_memory_datasource.hpp
+++ b/src/mapnik_memory_datasource.hpp
@@ -29,7 +29,7 @@ class MemoryDatasource: public node::ObjectWrap {
   private:
     ~MemoryDatasource();
     mapnik::datasource_ptr datasource_;
-    unsigned int count_;
+    unsigned int feature_id_;
     boost::scoped_ptr<mapnik::transcoder> tr_;
 };
 
diff --git a/src/mem_datasource.hpp b/src/mem_datasource.hpp
index 0c2c9a94c7..d00cd93954 100644
--- a/src/mem_datasource.hpp
+++ b/src/mem_datasource.hpp
@@ -87,7 +87,7 @@ class js_featureset : public mapnik::Featureset, private boost::noncopyable
 public:
     js_featureset( const mapnik::query& q, const js_datasource* ds)
         : q_(q),
-          count_(0),
+          feature_id_(1),
           tr_(new mapnik::transcoder("utf-8")),
           ds_(ds),
           obj_(Object::New())
@@ -130,7 +130,8 @@ class js_featureset : public mapnik::Featureset, private boost::noncopyable
                         {
                             mapnik::geometry_type * pt = new mapnik::geometry_type(mapnik::Point);
                             pt->move_to(x->NumberValue(),y->NumberValue());
-                            mapnik::feature_ptr feature(new mapnik::Feature(count_));
+                            mapnik::feature_ptr feature(new mapnik::Feature(feature_id_));
+                            ++feature_id_;
                             feature->add_geometry(pt);
                             if (obj->Has(String::New("properties")))
                             {
@@ -164,7 +165,6 @@ class js_featureset : public mapnik::Featureset, private boost::noncopyable
                                     }
                                 }
                             }
-                            ++count_;
                             return feature;                
                         }
                     }
@@ -177,7 +177,7 @@ class js_featureset : public mapnik::Featureset, private boost::noncopyable
         
 private:
     mapnik::query const& q_;
-    unsigned int count_;
+    unsigned int feature_id_;
     boost::scoped_ptr<mapnik::transcoder> tr_;
     const js_datasource* ds_;
     Local<Object> obj_;