diff --git a/README.md b/README.md
index 3418f98..e5c40b6 100644
--- a/README.md
+++ b/README.md
@@ -19,11 +19,12 @@ Install
 
     npm install ndarray-pack
 
-### `require("ndarray-pack")(nested_array[,out])`
+### `require("ndarray-pack")(nested_array[,out, [Type]])`
 Converts the nested array into a packed ndarray.
 
 * `nested_array` is an array-of-arrays (ie a numeric.js array)
 * `out` is an optional ndarray that gets the result of unpacking `array`
+* `Type` is an optional type. This is the underlying type of the generated ndarray, default to Float64Array
 
 **Returns** A packed ndarray representation of the nested arrays.
 
diff --git a/convert.js b/convert.js
index fcd9e62..595f77a 100644
--- a/convert.js
+++ b/convert.js
@@ -3,7 +3,10 @@
 var ndarray = require("ndarray")
 var do_convert = require("./doConvert.js")
 
-module.exports = function convert(arr, result) {
+module.exports = function convert(arr, result, Type) {
+  if (typeof Type === 'undefined') {
+    Type = Float64Array;
+  }
   var shape = [], c = arr, sz = 1
   while(Array.isArray(c)) {
     shape.push(c.length)
@@ -14,7 +17,7 @@ module.exports = function convert(arr, result) {
     return ndarray()
   }
   if(!result) {
-    result = ndarray(new Float64Array(sz), shape)
+    result = ndarray(new Type(sz), shape)
   }
   do_convert(result, arr)
   return result
diff --git a/test/test.js b/test/test.js
index 2e62b68..13e91ea 100644
--- a/test/test.js
+++ b/test/test.js
@@ -22,4 +22,16 @@ require("tap").test("ndarray-pack", function(t) {
   t.equals(y.get(0, 0, 0), 1)
 
   t.end()
-})
\ No newline at end of file
+})
+
+require("tap").test("ndarray-pack", function(t) {
+
+  var x = [[1, 0, 1],
+           [0, 1, 1],
+           [0, 0, 1],
+           [1, 0, 0]]
+
+  var y = require("../convert.js")(x, undefined, Float32Array)
+  t.type(y.data, Float32Array);
+  t.end()
+})