diff --git a/README.md b/README.md
index b04c03e0..ca2084f5 100644
--- a/README.md
+++ b/README.md
@@ -29,9 +29,8 @@ Or in a browser
 ```js
 var shpwrite = require('shp-write');
 
-// (optional) set names for feature types and zipped folder
+// (optional) set names for feature types
 var options = {
-    folder: 'myshapes',
     types: {
         point: 'mypoints',
         polygon: 'mypolygons',
@@ -67,6 +66,15 @@ shpwrite.download({
 // triggers a download of a zip file with shapefiles contained within.
 ```
 
+## Custom .prj file
+To pass a custom [WKT string](http://www.opengeospatial.org/standards/wkt-crs) in the .prj file to define a different projection the prj option can be used:
+
+```js
+var options = {
+    prj: 'PROJCS["Amersfoort / RD New",GEOGCS["Amersfoort",DATUM["D_Amersfoort",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Stereographic_North_Pole"],PARAMETER["standard_parallel_1",52.15616055555555],PARAMETER["central_meridian",5.38763888888889],PARAMETER["scale_factor",0.9999079],PARAMETER["false_easting",155000],PARAMETER["false_northing",463000],UNIT["Meter",1]]'
+}
+```
+
 ## API
 
 ### `download(geojson)`
diff --git a/src/zip.js b/src/zip.js
index b8e89d85..98551ddc 100644
--- a/src/zip.js
+++ b/src/zip.js
@@ -1,12 +1,12 @@
 var write = require('./write'),
     geojson = require('./geojson'),
-    prj = require('./prj'),
+    defaultPrj = require('./prj'),
     JSZip = require('jszip');
 
 module.exports = function(gj, options) {
 
-    var zip = new JSZip(),
-        layers = zip.folder(options && options.folder ? options.folder : 'layers');
+    var zip = new JSZip();
+    var prj = (options && options.prj) ? options.prj : defaultPrj;
 
     [geojson.point(gj), geojson.line(gj), geojson.polygon(gj)]
         .forEach(function(l) {
@@ -20,10 +20,10 @@ module.exports = function(gj, options) {
                 l.geometries,
                 function(err, files) {
                     var fileName = options && options.types[l.type.toLowerCase()] ? options.types[l.type.toLowerCase()] : l.type;
-                    layers.file(fileName + '.shp', files.shp.buffer, { binary: true });
-                    layers.file(fileName + '.shx', files.shx.buffer, { binary: true });
-                    layers.file(fileName + '.dbf', files.dbf.buffer, { binary: true });
-                    layers.file(fileName + '.prj', prj);
+                    zip.file(fileName + '.shp', files.shp.buffer, { binary: true });
+                    zip.file(fileName + '.shx', files.shx.buffer, { binary: true });
+                    zip.file(fileName + '.dbf', files.dbf.buffer, { binary: true });
+                    zip.file(fileName + '.prj', prj);
                 });
         }
     });