diff --git a/src/lib.rs b/src/lib.rs
index 033d72c2..2e3bda31 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -576,7 +576,7 @@ pub fn inv_rotate<V, M: Rotate<V>>(m: &M, v: &V) -> V {
 
 /// Rotates a copy of `m` by `amount` using `center` as the pivot point.
 #[inline(always)]
-pub fn append_rotation_wrt_point<LV: Neg<LV>,
+pub fn append_rotation_wrt_point<LV: Neg<LV> + Copy,
                                  AV,
                                  M: RotationWithTranslation<LV, AV>>(
                                  m:      &M,
@@ -587,7 +587,7 @@ pub fn append_rotation_wrt_point<LV: Neg<LV>,
 
 /// Rotates a copy of `m` by `amount` using `m.translation()` as the pivot point.
 #[inline(always)]
-pub fn append_rotation_wrt_center<LV: Neg<LV>,
+pub fn append_rotation_wrt_center<LV: Neg<LV> + Copy,
                                   AV,
                                   M: RotationWithTranslation<LV, AV>>(
                                   m:      &M,
diff --git a/src/structs/dvec_macros.rs b/src/structs/dvec_macros.rs
index 1e0adbdb..8ee1f762 100644
--- a/src/structs/dvec_macros.rs
+++ b/src/structs/dvec_macros.rs
@@ -250,9 +250,9 @@ macro_rules! dvec_impl(
             }
         }
 
-        impl<N: Neg<N> + Zero> Neg<$dvec<N>> for $dvec<N> {
+        impl<N: Neg<N> + Zero + Copy> Neg<$dvec<N>> for $dvec<N> {
             #[inline]
-            fn neg(&self) -> $dvec<N> {
+            fn neg(self) -> $dvec<N> {
                 FromIterator::from_iter(self.as_slice().iter().map(|a| -*a))
             }
         }
diff --git a/src/structs/quat.rs b/src/structs/quat.rs
index 1a92628a..464884f0 100644
--- a/src/structs/quat.rs
+++ b/src/structs/quat.rs
@@ -54,7 +54,7 @@ impl<N> Quat<N> {
     }
 }
 
-impl<N: Neg<N>> Quat<N> {
+impl<N: Neg<N> + Copy> Quat<N> {
     /// Replaces this quaternion by its conjugate.
     #[inline]
     pub fn conjugate(&mut self) {
diff --git a/src/structs/rot.rs b/src/structs/rot.rs
index cc5da36d..09ecea2a 100644
--- a/src/structs/rot.rs
+++ b/src/structs/rot.rs
@@ -18,7 +18,7 @@ pub struct Rot2<N> {
     submat: Mat2<N>
 }
 
-impl<N: Clone + BaseFloat + Neg<N>> Rot2<N> {
+impl<N: Clone + BaseFloat + Neg<N> + Copy> Rot2<N> {
     /// Builds a 2 dimensional rotation matrix from an angle in radian.
     pub fn new(angle: Vec1<N>) -> Rot2<N> {
         let (sia, coa) = angle.x.sin_cos();
@@ -66,7 +66,7 @@ impl<N: BaseFloat + Clone> Rotation<Vec1<N>> for Rot2<N> {
     }
 }
 
-impl<N: Clone + Rand + BaseFloat + Neg<N>> Rand for Rot2<N> {
+impl<N: Clone + Rand + BaseFloat + Neg<N> + Copy> Rand for Rot2<N> {
     #[inline]
     fn rand<R: Rng>(rng: &mut R) -> Rot2<N> {
         Rot2::new(rng.gen())
diff --git a/src/structs/spec/vec0.rs b/src/structs/spec/vec0.rs
index c1864867..683b3e12 100644
--- a/src/structs/spec/vec0.rs
+++ b/src/structs/spec/vec0.rs
@@ -112,9 +112,9 @@ impl<N, T> Sub<T, vec::Vec0<N>> for vec::Vec0<N> {
     }
 }
 
-impl<N: Neg<N>> Neg<vec::Vec0<N>> for vec::Vec0<N> {
+impl<N: Neg<N> + Copy> Neg<vec::Vec0<N>> for vec::Vec0<N> {
     #[inline]
-    fn neg(&self) -> vec::Vec0<N> {
+    fn neg(self) -> vec::Vec0<N> {
         vec::Vec0
     }
 }
diff --git a/src/structs/vec_macros.rs b/src/structs/vec_macros.rs
index 8f5aa036..f33e0644 100644
--- a/src/structs/vec_macros.rs
+++ b/src/structs/vec_macros.rs
@@ -480,9 +480,9 @@ macro_rules! scalar_div_impl(
 
 macro_rules! neg_impl(
     ($t: ident, $comp0: ident $(,$compN: ident)*) => (
-        impl<N: Neg<N>> Neg<$t<N>> for $t<N> {
+        impl<N: Neg<N> + Copy> Neg<$t<N>> for $t<N> {
             #[inline]
-            fn neg(&self) -> $t<N> {
+            fn neg(self) -> $t<N> {
                 $t::new(-self.$comp0 $(, -self.$compN )*)
             }
         }
diff --git a/src/traits/geometry.rs b/src/traits/geometry.rs
index 3ac68557..ac7306cc 100644
--- a/src/traits/geometry.rs
+++ b/src/traits/geometry.rs
@@ -82,7 +82,7 @@ pub trait Rotate<V> {
 ///
 /// Those operations are automatically implemented in term of the `Rotation` and `Translation`
 /// traits.
-pub trait RotationWithTranslation<LV: Neg<LV>, AV>: Rotation<AV> + Translation<LV> {
+pub trait RotationWithTranslation<LV: Neg<LV> + Copy, AV>: Rotation<AV> + Translation<LV> {
     /// Applies a rotation centered on a specific point.
     ///
     /// # Arguments
@@ -136,7 +136,7 @@ pub trait RotationWithTranslation<LV: Neg<LV>, AV>: Rotation<AV> + Translation<L
     }
 }
 
-impl<LV: Neg<LV>, AV, M: Rotation<AV> + Translation<LV>> RotationWithTranslation<LV, AV> for M {
+impl<LV: Neg<LV> + Copy, AV, M: Rotation<AV> + Translation<LV>> RotationWithTranslation<LV, AV> for M {
 }
 
 /// Trait of transformation having a rotation extractable as a rotation matrix. This can typically