diff --git a/src/angle.rs b/src/angle.rs
index da928f0..fa7191e 100644
--- a/src/angle.rs
+++ b/src/angle.rs
@@ -23,7 +23,7 @@ use std::ops::*;
 use rand::{Rand, Rng};
 use rand::distributions::range::SampleRange;
 
-use rust_num::{One, Zero, one, zero};
+use rust_num::{Float, One, Zero, one, zero};
 
 use approx::ApproxEq;
 use num::BaseFloat;
@@ -52,11 +52,27 @@ pub trait ToDeg<S: BaseFloat> {
     fn to_deg(&self) -> Deg<S>;
 }
 
-impl<S: BaseFloat> ToRad<S> for Rad<S> { #[inline] fn to_rad(&self) -> Rad<S> { self.clone() } }
-impl<S: BaseFloat> ToRad<S> for Deg<S> { #[inline] fn to_rad(&self) -> Rad<S> { rad(self.s.to_radians()) } }
+impl<S: BaseFloat> ToRad<S> for Rad<S> {
+    #[inline]
+    fn to_rad(&self) -> Rad<S> { self.clone() }
+}
+impl<S: BaseFloat> ToRad<S> for Deg<S> {
+    #[inline]
+    fn to_rad(&self) -> Rad<S> {
+        rad(self.s * cast(f64::consts::PI / 180.0).unwrap())
+    }
+}
 
-impl<S: BaseFloat> ToDeg<S> for Rad<S> { #[inline] fn to_deg(&self) -> Deg<S> { deg(self.s.to_degrees()) } }
-impl<S: BaseFloat> ToDeg<S> for Deg<S> { #[inline] fn to_deg(&self) -> Deg<S> { self.clone() } }
+impl<S: BaseFloat> ToDeg<S> for Rad<S> {
+    #[inline]
+    fn to_deg(&self) -> Deg<S> {
+        deg(self.s * cast(180.0 / f64::consts::PI).unwrap())
+    }
+}
+impl<S: BaseFloat> ToDeg<S> for Deg<S> {
+    #[inline]
+    fn to_deg(&self) -> Deg<S> { self.clone() }
+}
 
 /// Private utility functions for converting to/from scalars
 trait ScalarConv<S> {
diff --git a/src/approx.rs b/src/approx.rs
index f391c7e..5a12903 100644
--- a/src/approx.rs
+++ b/src/approx.rs
@@ -13,10 +13,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::num::cast;
+use std::num::{NumCast, cast};
 use rust_num::Float;
 
-pub trait ApproxEq<T: Float>: Sized {
+pub trait ApproxEq<T: NumCast + Float>: Sized {
     fn approx_epsilon(_hack: Option<Self>) -> T {
         cast(1.0e-5f64).unwrap()
     }
diff --git a/src/lib.rs b/src/lib.rs
index c44f878..6d578ea 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,7 +15,7 @@
 
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
-#![feature(plugin, core, std_misc, custom_derive)]
+#![feature(plugin, core, custom_derive)]
 
 //! Computer graphics-centric math.
 //!
diff --git a/src/num.rs b/src/num.rs
index e2e4a32..9d68a2d 100644
--- a/src/num.rs
+++ b/src/num.rs
@@ -17,9 +17,9 @@ use approx::ApproxEq;
 
 use std::cmp;
 use std::fmt;
-use std::ops::*;
+use std::num::NumCast;
 
-use rust_num::{Float, Num, NumCast};
+use rust_num::{Float, Num};
 
 /// A trait providing a [partial ordering](http://mathworld.wolfram.com/PartialOrder.html).
 pub trait PartialOrd {
diff --git a/src/vector.rs b/src/vector.rs
index af2ee69..03a9da3 100644
--- a/src/vector.rs
+++ b/src/vector.rs
@@ -98,11 +98,12 @@
 
 use std::fmt;
 use std::mem;
+use std::num::NumCast;
 use std::ops::*;
 
 use rand::{Rand, Rng};
 
-use rust_num::{NumCast, Zero, One, zero, one};
+use rust_num::{Zero, One, zero, one};
 
 use angle::{Rad, atan2, acos};
 use approx::ApproxEq;