diff --git a/Cargo.toml b/Cargo.toml
index e3f8690..27dd698 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,8 +13,7 @@ plugins = ["serde", "serde_macros", "heapsize", "heapsize_plugin"]
 
 [dependencies]
 rustc-serialize = "0.3.2"
-rand = "0.3.7"
-num = "0.1.24"
+num = {version = "0.1.24", default-features = false}
 log = "0.3.1"
 serde = {version = "*", optional = true}
 serde_macros = {version = "*", optional = true}
@@ -27,3 +26,5 @@ optional = true
 version = "0.1.0"
 optional = true
 
+[dev-dependencies]
+rand = "0.3.7"
diff --git a/src/lib.rs b/src/lib.rs
index 392fa11..971919c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,7 +7,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(asm, custom_derive, plugin, repr_simd, zero_one, test)]
+#![feature(asm, custom_derive, plugin, repr_simd, test)]
 #![feature(augmented_assignments)]
 #![feature(op_assign_traits)]
 
@@ -24,6 +24,7 @@ extern crate rustc_serialize;
 #[cfg(feature = "plugins")]
 extern crate serde;
 
+#[cfg(test)]
 extern crate rand;
 extern crate test;
 extern crate num as num_lib;
diff --git a/src/num.rs b/src/num.rs
index 93c1bd3..ab4ab28 100644
--- a/src/num.rs
+++ b/src/num.rs
@@ -8,7 +8,7 @@
 // except according to those terms.
 //! A one-dimensional length, tagged with its units.
 
-use std::num;
+use num_lib as num;
 
 
 pub trait Zero {
diff --git a/src/point.rs b/src/point.rs
index e14aebe..32a6a61 100644
--- a/src/point.rs
+++ b/src/point.rs
@@ -13,7 +13,7 @@ use num::Zero;
 
 use num_lib::NumCast;
 use num_lib::traits;
-use std::fmt::{self, Formatter};
+use std::fmt;
 use std::ops::{Add, Neg, Mul, Sub, Div};
 
 #[derive(Clone, Copy, RustcDecodable, RustcEncodable, Eq, Hash, PartialEq)]
@@ -394,9 +394,9 @@ mod typedpoint2d {
     use scale_factor::ScaleFactor;
 
     #[derive(Debug, Copy, Clone)]
-    enum Mm {}
+    pub enum Mm {}
     #[derive(Debug, Copy, Clone)]
-    enum Cm {}
+    pub enum Cm {}
 
     pub type Point2DMm<T> = TypedPoint2D<Mm, T>;
     pub type Point2DCm<T> = TypedPoint2D<Cm, T>;
diff --git a/src/rect.rs b/src/rect.rs
index 8b9a15f..9cd8942 100644
--- a/src/rect.rs
+++ b/src/rect.rs
@@ -14,7 +14,7 @@ use size::Size2D;
 
 use num_lib::NumCast;
 use std::cmp::PartialOrd;
-use std::fmt::{self, Formatter};
+use std::fmt;
 use std::ops::{Add, Sub, Mul, Div};
 
 #[derive(Clone, Copy, RustcDecodable, RustcEncodable, PartialEq)]
diff --git a/src/size.rs b/src/size.rs
index 4c1ef61..f2a627f 100644
--- a/src/size.rs
+++ b/src/size.rs
@@ -11,7 +11,7 @@ use length::Length;
 use num::Zero;
 
 use num_lib::NumCast;
-use std::fmt::{self, Formatter};
+use std::fmt;
 use std::ops::{Mul, Div};
 
 #[derive(Clone, Copy, RustcDecodable, RustcEncodable, PartialEq)]