diff --git a/README.md b/README.md
index 96798a1..5aba088 100644
--- a/README.md
+++ b/README.md
@@ -116,8 +116,7 @@ considered valid values.  For instance, in the example above, the
 and any other value will be rejected.
 
 When parsing unknown fields, `"true"`, `"false"`, and `"null"` will be
-interpreted as their JavaScript equivalents, and numeric values will be
-interpreted as a number.
+interpreted as their JavaScript equivalents.
 
 You can also mix types and values, or multiple types, in a list.  For
 instance `{ blah: [Number, null] }` would allow a value to be set to
diff --git a/lib/nopt.js b/lib/nopt.js
index 9efab7a..223ebfe 100644
--- a/lib/nopt.js
+++ b/lib/nopt.js
@@ -50,7 +50,7 @@ function nopt (types, shorthands, args, slice) {
 function clean (data, types, typeDefs) {
   typeDefs = typeDefs || exports.typeDefs
   var remove = {}
-    , typeDefault = [false, true, null, String, Number, Array]
+    , typeDefault = [false, true, null, String, Array]
 
   Object.keys(data).forEach(function (k) {
     if (k === "argv") return
diff --git a/test/basic.js b/test/basic.js
index b31dccf..2f9088c 100644
--- a/test/basic.js
+++ b/test/basic.js
@@ -23,6 +23,14 @@ test("~ path is resolved to $HOME", function (t) {
   t.end()
 })
 
+// https://github.com/npm/nopt/issues/24
+test("Unknown options are not parsed as numbers", function (t) {
+    var parsed = nopt({"parse-me": Number}, null, ['--leave-as-is=1.20', '--parse-me=1.20'], 0)
+    t.equal(parsed['leave-as-is'], '1.20')
+    t.equal(parsed['parse-me'], 1.2)
+    t.end()
+});
+
 test("other tests", function (t) {
 
   var util = require("util")
@@ -170,7 +178,7 @@ test("other tests", function (t) {
      ,{t:["true"]}
      ,[]]
     ,["-aoa one -aoa null -aoa 100"
-     ,{aoa:["one", null, 100]}
+     ,{aoa:["one", null, '100']}
      ,[]]
     ,["-str 100"
      ,{str:"100"}