diff --git a/Cargo.toml b/Cargo.toml
index a396ec5..0aa8c88 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 
 name = "cgmath"
-version = "0.1.2"
+version = "0.1.3"
 authors = ["Brendan Zabarauskas <bjzaba@yahoo.com.au>",
         "Brian Heylin",
         "Colin Sherratt",
diff --git a/src/matrix.rs b/src/matrix.rs
index 2d7f9e6..8720071 100644
--- a/src/matrix.rs
+++ b/src/matrix.rs
@@ -44,7 +44,7 @@ pub struct Matrix3<S> { pub x: Vector3<S>, pub y: Vector3<S>, pub z: Vector3<S>
 pub struct Matrix4<S> { pub x: Vector4<S>, pub y: Vector4<S>, pub z: Vector4<S>, pub w: Vector4<S> }
 
 
-impl<S: BaseNum> Matrix2<S> {
+impl<S> Matrix2<S> {
     /// Create a new matrix, providing values for each index.
     #[inline]
     pub fn new(c0r0: S, c0r1: S,
@@ -58,7 +58,9 @@ impl<S: BaseNum> Matrix2<S> {
     pub fn from_cols(c0: Vector2<S>, c1: Vector2<S>) -> Matrix2<S> {
         Matrix2 { x: c0, y: c1 }
     }
+}
 
+impl<S: BaseNum> Matrix2<S> {
     /// Create a new diagonal matrix, providing a single value to use for each
     /// non-zero index.
     #[inline]
@@ -98,6 +100,15 @@ impl<S: BaseFloat + 'static> Matrix2<S> {
     }
 }
 
+impl<S: Copy + Neg<Output = S>> Matrix2<S> {
+    /// Negate this `Matrix2` in-place.
+    #[inline]
+    pub fn neg_self(&mut self) {
+        (&mut self[0]).neg_self();
+        (&mut self[1]).neg_self();
+    }
+}
+
 impl<S: BaseNum> Matrix3<S> {
     /// Create a new matrix, providing values for each index.
     #[inline]
@@ -137,8 +148,7 @@ impl<S: BaseNum> Matrix3<S> {
     }
 }
 
-impl<S: BaseFloat + 'static>
-Matrix3<S> {
+impl<S: BaseFloat + 'static> Matrix3<S> {
     /// Create a transformation matrix that will cause a vector to point at
     /// `dir`, using `up` for orientation.
     pub fn look_at(dir: &Vector3<S>, up: &Vector3<S>) -> Matrix3<S> {
@@ -220,6 +230,16 @@ Matrix3<S> {
     }
 }
 
+impl<S: Copy + Neg<Output = S>> Matrix3<S> {
+    /// Negate this `Matrix3` in-place.
+    #[inline]
+    pub fn neg_self(&mut self) {
+        (&mut self[0]).neg_self();
+        (&mut self[1]).neg_self();
+        (&mut self[2]).neg_self();
+    }
+}
+
 impl<S: BaseNum> Matrix4<S> {
     /// Create a new matrix, providing values for each index.
     #[inline]
@@ -271,8 +291,7 @@ impl<S: BaseNum> Matrix4<S> {
     }
 }
 
-impl<S: BaseFloat>
-Matrix4<S> {
+impl<S: BaseFloat> Matrix4<S> {
     /// Create a transformation matrix that will cause a vector to point at
     /// `dir`, using `up` for orientation.
     pub fn look_at(eye: &Point3<S>, center: &Point3<S>, up: &Vector3<S>) -> Matrix4<S> {
@@ -287,8 +306,18 @@ Matrix4<S> {
     }
 }
 
+impl<S: Copy + Neg<Output = S>> Matrix4<S> {
+    /// Negate this `Matrix4` in-place.
+    #[inline]
+    pub fn neg_self(&mut self) {
+        (&mut self[0]).neg_self();
+        (&mut self[1]).neg_self();
+        (&mut self[2]).neg_self();
+        (&mut self[3]).neg_self();
+    }
+}
+
 pub trait Matrix<S: BaseFloat, V: Clone + Vector<S>>: Array2<V, V, S>
-                                                    + Neg
                                                     + Zero + One
                                                     + ApproxEq<S>
                                                     + Sized {
@@ -317,9 +346,6 @@ pub trait Matrix<S: BaseFloat, V: Clone + Vector<S>>: Array2<V, V, S>
     #[must_use]
     fn mul_m(&self, m: &Self) -> Self;
 
-    /// Negate this matrix in-place (multiply by scalar -1).
-    fn neg_self(&mut self);
-
     /// Multiply this matrix by a scalar, in-place.
     fn mul_self_s(&mut self, s: S);
     /// Divide this matrix by a scalar, in-place.
@@ -423,11 +449,13 @@ impl<S: BaseFloat + 'static> Sub for Matrix4<S> {
     fn sub(self, other: Matrix4<S>) -> Matrix4<S> { self.sub_m(&other) }
 }
 
-impl<S: BaseFloat> Neg for Matrix2<S> {
-    type Output = Matrix2<S>;
+impl<S: Neg> Neg for Matrix2<S> {
+    type Output = Matrix2<S::Output>;
 
     #[inline]
-    fn neg(self) -> Matrix2<S> { Matrix2::from_cols(self[0].neg(), self[1].neg()) }
+    fn neg(self) -> Matrix2<S::Output> {
+        Matrix2::from_cols(self.x.neg(), self.y.neg())
+    }
 }
 
 impl<S: BaseFloat> Neg for Matrix3<S> {
@@ -795,12 +823,6 @@ impl<S: BaseFloat + 'static> Matrix<S, Vector2<S>> for Matrix2<S> {
                      self.row(0).dot(&other[1]), self.row(1).dot(&other[1]))
     }
 
-    #[inline]
-    fn neg_self(&mut self) {
-        (&mut self[0]).neg_self();
-        (&mut self[1]).neg_self();
-    }
-
     #[inline]
     fn mul_self_s(&mut self, s: S) {
         (&mut self[0]).mul_self_s(s);
@@ -926,13 +948,6 @@ impl<S: BaseFloat + 'static> Matrix<S, Vector3<S>> for Matrix3<S> {
                      self.row(0).dot(&other[2]),self.row(1).dot(&other[2]),self.row(2).dot(&other[2]))
     }
 
-    #[inline]
-    fn neg_self(&mut self) {
-        (&mut self[0]).neg_self();
-        (&mut self[1]).neg_self();
-        (&mut self[2]).neg_self();
-    }
-
     #[inline]
     fn mul_self_s(&mut self, s: S) {
         (&mut self[0]).mul_self_s(s);
@@ -1094,14 +1109,6 @@ impl<S: BaseFloat + 'static> Matrix<S, Vector4<S>> for Matrix4<S> {
                      dot_matrix4!(self, other, 0, 3), dot_matrix4!(self, other, 1, 3), dot_matrix4!(self, other, 2, 3), dot_matrix4!(self, other, 3, 3))
     }
 
-    #[inline]
-    fn neg_self(&mut self) {
-        (&mut self[0]).neg_self();
-        (&mut self[1]).neg_self();
-        (&mut self[2]).neg_self();
-        (&mut self[3]).neg_self();
-    }
-
     #[inline]
     fn mul_self_s(&mut self, s: S) {
         (&mut self[0]).mul_self_s(s);
diff --git a/src/num.rs b/src/num.rs
index 7de7ebf..cbd5744 100644
--- a/src/num.rs
+++ b/src/num.rs
@@ -72,7 +72,7 @@ pub trait One {
 /// Base numeric types with partial ordering
 pub trait BaseNum:
     Copy + NumCast + Clone + Add<Output=Self> + Sub<Output=Self> +
-    Mul<Output=Self> + Div<Output=Self> + Rem<Output=Self> + Neg<Output=Self> + PartialEq
+    Mul<Output=Self> + Div<Output=Self> + Rem<Output=Self> + PartialEq
     + PartialOrd + cmp::PartialOrd + fmt::Debug + Zero + One
 {}
 
diff --git a/src/vector.rs b/src/vector.rs
index 7f32b8e..4cc8581 100644
--- a/src/vector.rs
+++ b/src/vector.rs
@@ -111,7 +111,7 @@ use num::{BaseNum, BaseFloat, Zero, One, zero, one};
 /// A trait that specifies a range of numeric operations for vectors. Not all
 /// of these make sense from a linear algebra point of view, but are included
 /// for pragmatic reasons.
-pub trait Vector<S: BaseNum>: Array1<S> + Zero + One + Neg<Output=Self> {
+pub trait Vector<S: BaseNum>: Array1<S> + Zero + One {
     /// Construct a vector from a single value, replicating it.
     fn from_value(s: S) -> Self;
     /// Add a scalar to this vector, returning a new vector.
@@ -146,9 +146,6 @@ pub trait Vector<S: BaseNum>: Array1<S> + Zero + One + Neg<Output=Self> {
     #[must_use]
     fn rem_v(&self, v: &Self) -> Self;
 
-    /// Negate this vector in-place.
-    fn neg_self(&mut self);
-
     /// Add a scalar to this vector in-place.
     fn add_self_s(&mut self, s: S);
     /// Subtract a scalar from this vector, in-place.
@@ -203,6 +200,14 @@ macro_rules! vec(
             }
         }
 
+        impl<$S: Copy + Neg<Output = $S>> $Self_<$S> {
+            /// Negate this vector in-place (multiply by -1).
+            #[inline]
+            pub fn neg_self(&mut self) {
+                $(self.$field = -self.$field);+
+            }
+        }
+
         /// The short constructor.
         #[inline]
         pub fn $constructor<S>($($field: S),+) -> $Self_<S> {
@@ -300,8 +305,6 @@ macro_rules! vec(
             #[inline] fn div_v(&self, v: &$Self_<S>) -> $Self_<S> { $Self_::new($(self.$field / v.$field),+) }
             #[inline] fn rem_v(&self, v: &$Self_<S>) -> $Self_<S> { $Self_::new($(self.$field % v.$field),+) }
 
-            #[inline] fn neg_self(&mut self) { $(self.$field = -self.$field;)+ }
-
             #[inline] fn add_self_s(&mut self, s: S) { $(self.$field = self.$field + s;)+ }
             #[inline] fn sub_self_s(&mut self, s: S) { $(self.$field = self.$field - s;)+ }
             #[inline] fn mul_self_s(&mut self, s: S) { $(self.$field = self.$field * s;)+ }
@@ -334,11 +337,11 @@ macro_rules! vec(
             fn sub(self, v: $Self_<S>) -> $Self_<S> { self.sub_v(&v) }
         }
 
-        impl<S: BaseNum> Neg for $Self_<S> {
-            type Output = $Self_<S>;
+        impl<S: Neg> Neg for $Self_<S> {
+            type Output = $Self_<S::Output>;
 
             #[inline]
-            fn neg(self) -> $Self_<S> { $Self_::new($(-self.$field),+) }
+            fn neg(self) -> $Self_<S::Output> { $Self_::new($(-self.$field),+) }
         }
 
         impl<S: BaseNum> Mul for $Self_<S> {