diff --git a/src/core/matrix.rs b/src/core/matrix.rs
index ec6f458b..949ef043 100644
--- a/src/core/matrix.rs
+++ b/src/core/matrix.rs
@@ -1,12 +1,12 @@
 use num::Zero;
 use num_complex::Complex;
 
-use std::cmp::Ordering;
-use std::marker::PhantomData;
-use std::fmt;
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use std::any::TypeId;
+use std::cmp::Ordering;
+use std::fmt;
+use std::marker::PhantomData;
 use std::mem;
-use approx::ApproxEq;
 
 #[cfg(feature = "serde-serialize")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
@@ -16,13 +16,14 @@ use abomonation::Abomonation;
 
 use alga::general::{Real, Ring};
 
-use core::{DefaultAllocator, MatrixMN, MatrixN, Scalar, Unit, VectorN};
-use core::dimension::{Dim, DimAdd, DimSum, U1, U2, U3};
-use core::constraint::{DimEq, SameNumberOfColumns, SameNumberOfRows, ShapeConstraint};
-use core::iter::{MatrixIter, MatrixIterMut};
 use core::allocator::{Allocator, SameShapeAllocator, SameShapeC, SameShapeR};
-use core::storage::{ContiguousStorage, ContiguousStorageMut, Owned, SameShapeStorage, Storage,
-                    StorageMut};
+use core::constraint::{DimEq, SameNumberOfColumns, SameNumberOfRows, ShapeConstraint};
+use core::dimension::{Dim, DimAdd, DimSum, U1, U2, U3};
+use core::iter::{MatrixIter, MatrixIterMut};
+use core::storage::{
+    ContiguousStorage, ContiguousStorageMut, Owned, SameShapeStorage, Storage, StorageMut,
+};
+use core::{DefaultAllocator, MatrixMN, MatrixN, Scalar, Unit, VectorN};
 
 /// A square matrix.
 pub type SquareMatrix<N, D, S> = Matrix<N, D, D, S>;
@@ -80,7 +81,8 @@ pub struct Matrix<N: Scalar, R: Dim, C: Dim, S> {
 
 impl<N: Scalar, R: Dim, C: Dim, S: fmt::Debug> fmt::Debug for Matrix<N, R, C, S> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        formatter.debug_struct("Matrix")
+        formatter
+            .debug_struct("Matrix")
             .field("data", &self.data)
             .finish()
     }
@@ -224,7 +226,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
     /// Tests whether `self` and `rhs` are equal up to a given epsilon.
     ///
-    /// See `relative_eq` from the `ApproxEq` trait for more details.
+    /// See `relative_eq` from the `RelativeEq` trait for more details.
     #[inline]
     pub fn relative_eq<R2, C2, SB>(
         &self,
@@ -233,7 +235,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
         max_relative: N::Epsilon,
     ) -> bool
     where
-        N: ApproxEq,
+        N: RelativeEq,
         R2: Dim,
         C2: Dim,
         SB: Storage<N, R2, C2>,
@@ -740,9 +742,9 @@ impl<N: Scalar + Zero, D: DimAdd<U1>, S: Storage<N, D>> Vector<N, D, S> {
     }
 }
 
-impl<N, R: Dim, C: Dim, S> ApproxEq for Matrix<N, R, C, S>
+impl<N, R: Dim, C: Dim, S> AbsDiffEq for Matrix<N, R, C, S>
 where
-    N: Scalar + ApproxEq,
+    N: Scalar + AbsDiffEq,
     S: Storage<N, R, C>,
     N::Epsilon: Copy,
 {
@@ -753,16 +755,25 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.iter()
+            .zip(other.iter())
+            .all(|(a, b)| a.abs_diff_eq(b, epsilon))
+    }
+}
+
+impl<N, R: Dim, C: Dim, S> RelativeEq for Matrix<N, R, C, S>
+where
+    N: Scalar + RelativeEq,
+    S: Storage<N, R, C>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -772,6 +783,18 @@ where
     ) -> bool {
         self.relative_eq(other, epsilon, max_relative)
     }
+}
+
+impl<N, R: Dim, C: Dim, S> UlpsEq for Matrix<N, R, C, S>
+where
+    N: Scalar + UlpsEq,
+    S: Storage<N, R, C>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
@@ -1165,9 +1188,9 @@ impl<N: Real, R: Dim, C: Dim, S: StorageMut<N, R, C>> Matrix<N, R, C, S> {
     }
 }
 
-impl<N, R: Dim, C: Dim, S> ApproxEq for Unit<Matrix<N, R, C, S>>
+impl<N, R: Dim, C: Dim, S> AbsDiffEq for Unit<Matrix<N, R, C, S>>
 where
-    N: Scalar + ApproxEq,
+    N: Scalar + AbsDiffEq,
     S: Storage<N, R, C>,
     N::Epsilon: Copy,
 {
@@ -1178,16 +1201,23 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.as_ref().abs_diff_eq(other.as_ref(), epsilon)
+    }
+}
+
+impl<N, R: Dim, C: Dim, S> RelativeEq for Unit<Matrix<N, R, C, S>>
+where
+    N: Scalar + RelativeEq,
+    S: Storage<N, R, C>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -1198,6 +1228,18 @@ where
         self.as_ref()
             .relative_eq(other.as_ref(), epsilon, max_relative)
     }
+}
+
+impl<N, R: Dim, C: Dim, S> UlpsEq for Unit<Matrix<N, R, C, S>>
+where
+    N: Scalar + UlpsEq,
+    S: Storage<N, R, C>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/core/properties.rs b/src/core/properties.rs
index 335e9ba1..5a77e8f3 100644
--- a/src/core/properties.rs
+++ b/src/core/properties.rs
@@ -1,13 +1,13 @@
 // Matrix properties checks.
+use approx::RelativeEq;
 use num::{One, Zero};
-use approx::ApproxEq;
 
 use alga::general::{ClosedAdd, ClosedMul, Real};
 
-use core::{DefaultAllocator, Matrix, Scalar, SquareMatrix};
+use core::allocator::Allocator;
 use core::dimension::{Dim, DimMin};
 use core::storage::Storage;
-use core::allocator::Allocator;
+use core::{DefaultAllocator, Matrix, Scalar, SquareMatrix};
 
 impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     /// Indicates if this is a square matrix.
@@ -24,7 +24,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
         nrows == ncols
     }
 
-    // FIXME: ApproxEq prevents us from using those methods on integer matrices…
+    // FIXME: RelativeEq prevents us from using those methods on integer matrices…
     /// Indicated if this is the identity matrix within a relative error of `eps`.
     ///
     /// If the matrix is diagonal, this checks that diagonal elements (i.e. at coordinates `(i, i)`
@@ -32,7 +32,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     #[inline]
     pub fn is_identity(&self, eps: N::Epsilon) -> bool
     where
-        N: Zero + One + ApproxEq,
+        N: Zero + One + RelativeEq,
         N::Epsilon: Copy,
     {
         let (nrows, ncols) = self.shape();
@@ -90,7 +90,7 @@ impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
     #[inline]
     pub fn is_orthogonal(&self, eps: N::Epsilon) -> bool
     where
-        N: Zero + One + ClosedAdd + ClosedMul + ApproxEq,
+        N: Zero + One + ClosedAdd + ClosedMul + RelativeEq,
         S: Storage<N, R, C>,
         N::Epsilon: Copy,
         DefaultAllocator: Allocator<N, C, C>,
diff --git a/src/core/unit.rs b/src/core/unit.rs
index 24d5382b..d8df3e82 100644
--- a/src/core/unit.rs
+++ b/src/core/unit.rs
@@ -1,6 +1,6 @@
+use approx::RelativeEq;
 use std::mem;
 use std::ops::{Deref, Neg};
-use approx::ApproxEq;
 
 #[cfg(feature = "serde-serialize")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
@@ -138,7 +138,7 @@ impl<T> AsRef<T> for Unit<T> {
  */
 impl<T: NormedSpace> SubsetOf<T> for Unit<T>
 where
-    T::Field: ApproxEq,
+    T::Field: RelativeEq,
 {
     #[inline]
     fn to_superset(&self) -> T {
@@ -156,7 +156,7 @@ where
     }
 }
 
-// impl<T: ApproxEq> ApproxEq for Unit<T> {
+// impl<T: RelativeEq> RelativeEq for Unit<T> {
 //     type Epsilon = T::Epsilon;
 //
 //     #[inline]
diff --git a/src/geometry/isometry.rs b/src/geometry/isometry.rs
index 8c582275..86aca469 100644
--- a/src/geometry/isometry.rs
+++ b/src/geometry/isometry.rs
@@ -1,7 +1,7 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use std::fmt;
 use std::hash;
 use std::marker::PhantomData;
-use approx::ApproxEq;
 
 #[cfg(feature = "serde-serialize")]
 use serde;
@@ -12,24 +12,36 @@ use abomonation::Abomonation;
 use alga::general::{Real, SubsetOf};
 use alga::linear::Rotation;
 
-use core::{DefaultAllocator, MatrixN};
+use core::allocator::Allocator;
 use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
 use core::storage::Owned;
-use core::allocator::Allocator;
+use core::{DefaultAllocator, MatrixN};
 use geometry::{Point, Translation};
 
 /// A direct isometry, i.e., a rotation followed by a translation.
 #[repr(C)]
 #[derive(Debug)]
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "serde-serialize",
-           serde(bound(serialize = "R: serde::Serialize,
+#[cfg_attr(
+    feature = "serde-serialize",
+    serde(
+        bound(
+            serialize = "R: serde::Serialize,
                      DefaultAllocator: Allocator<N, D>,
-                     Owned<N, D>: serde::Serialize")))]
-#[cfg_attr(feature = "serde-serialize",
-           serde(bound(deserialize = "R: serde::Deserialize<'de>,
+                     Owned<N, D>: serde::Serialize"
+        )
+    )
+)]
+#[cfg_attr(
+    feature = "serde-serialize",
+    serde(
+        bound(
+            deserialize = "R: serde::Deserialize<'de>,
                        DefaultAllocator: Allocator<N, D>,
-                       Owned<N, D>: serde::Deserialize<'de>")))]
+                       Owned<N, D>: serde::Deserialize<'de>"
+        )
+    )
+)]
 pub struct Isometry<N: Real, D: DimName, R>
 where
     DefaultAllocator: Allocator<N, D>,
@@ -201,9 +213,9 @@ where
     }
 }
 
-impl<N: Real, D: DimName, R> ApproxEq for Isometry<N, D, R>
+impl<N: Real, D: DimName, R> AbsDiffEq for Isometry<N, D, R>
 where
-    R: Rotation<Point<N, D>> + ApproxEq<Epsilon = N::Epsilon>,
+    R: Rotation<Point<N, D>> + AbsDiffEq<Epsilon = N::Epsilon>,
     DefaultAllocator: Allocator<N, D>,
     N::Epsilon: Copy,
 {
@@ -214,16 +226,24 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.translation.abs_diff_eq(&other.translation, epsilon)
+            && self.rotation.abs_diff_eq(&other.rotation, epsilon)
+    }
+}
+
+impl<N: Real, D: DimName, R> RelativeEq for Isometry<N, D, R>
+where
+    R: Rotation<Point<N, D>> + RelativeEq<Epsilon = N::Epsilon>,
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -236,6 +256,18 @@ where
             && self.rotation
                 .relative_eq(&other.rotation, epsilon, max_relative)
     }
+}
+
+impl<N: Real, D: DimName, R> UlpsEq for Isometry<N, D, R>
+where
+    R: Rotation<Point<N, D>> + UlpsEq<Epsilon = N::Epsilon>,
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/point.rs b/src/geometry/point.rs
index f12f0f8f..0f167a6d 100644
--- a/src/geometry/point.rs
+++ b/src/geometry/point.rs
@@ -1,8 +1,8 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use num::One;
-use std::hash;
-use std::fmt;
 use std::cmp::Ordering;
-use approx::ApproxEq;
+use std::fmt;
+use std::hash;
 
 #[cfg(feature = "serde-serialize")]
 use serde;
@@ -10,10 +10,10 @@ use serde;
 #[cfg(feature = "abomonation-serialize")]
 use abomonation::Abomonation;
 
-use core::{DefaultAllocator, Scalar, VectorN};
-use core::iter::{MatrixIter, MatrixIterMut};
-use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
 use core::allocator::Allocator;
+use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
+use core::iter::{MatrixIter, MatrixIterMut};
+use core::{DefaultAllocator, Scalar, VectorN};
 
 /// A point in a n-dimensional euclidean space.
 #[repr(C)]
@@ -183,7 +183,7 @@ where
     }
 }
 
-impl<N: Scalar + ApproxEq, D: DimName> ApproxEq for Point<N, D>
+impl<N: Scalar + AbsDiffEq, D: DimName> AbsDiffEq for Point<N, D>
 where
     DefaultAllocator: Allocator<N, D>,
     N::Epsilon: Copy,
@@ -195,16 +195,22 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.coords.abs_diff_eq(&other.coords, epsilon)
+    }
+}
+
+impl<N: Scalar + RelativeEq, D: DimName> RelativeEq for Point<N, D>
+where
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -215,6 +221,17 @@ where
         self.coords
             .relative_eq(&other.coords, epsilon, max_relative)
     }
+}
+
+impl<N: Scalar + UlpsEq, D: DimName> UlpsEq for Point<N, D>
+where
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/quaternion.rs b/src/geometry/quaternion.rs
index b1cba752..72fe0790 100644
--- a/src/geometry/quaternion.rs
+++ b/src/geometry/quaternion.rs
@@ -1,21 +1,21 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
+use num::Zero;
 use std::fmt;
 use std::hash;
-use num::Zero;
-use approx::ApproxEq;
 
-#[cfg(feature = "serde-serialize")]
-use serde;
 #[cfg(feature = "serde-serialize")]
 use core::storage::Owned;
+#[cfg(feature = "serde-serialize")]
+use serde;
 
 #[cfg(feature = "abomonation-serialize")]
 use abomonation::Abomonation;
 
 use alga::general::Real;
 
-use core::{Matrix3, MatrixN, MatrixSlice, MatrixSliceMut, Unit, Vector3, Vector4};
 use core::dimension::{U1, U3, U4};
 use core::storage::{CStride, RStride};
+use core::{Matrix3, MatrixN, MatrixSlice, MatrixSliceMut, Unit, Vector3, Vector4};
 
 use geometry::Rotation;
 
@@ -281,7 +281,7 @@ impl<N: Real> Quaternion<N> {
     }
 }
 
-impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for Quaternion<N> {
+impl<N: Real + AbsDiffEq<Epsilon = N>> AbsDiffEq for Quaternion<N> {
     type Epsilon = N;
 
     #[inline]
@@ -289,16 +289,20 @@ impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for Quaternion<N> {
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.as_vector().abs_diff_eq(other.as_vector(), epsilon) ||
+        // Account for the double-covering of S², i.e. q = -q
+       self.as_vector().iter().zip(other.as_vector().iter()).all(|(a, b)| a.abs_diff_eq(&-*b, epsilon))
+    }
+}
+
+impl<N: Real + RelativeEq<Epsilon = N>> RelativeEq for Quaternion<N> {
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -310,6 +314,13 @@ impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for Quaternion<N> {
         // Account for the double-covering of S², i.e. q = -q
        self.as_vector().iter().zip(other.as_vector().iter()).all(|(a, b)| a.relative_eq(&-*b, epsilon, max_relative))
     }
+}
+
+impl<N: Real + UlpsEq<Epsilon = N>> UlpsEq for Quaternion<N> {
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
@@ -613,7 +624,7 @@ impl<N: Real + fmt::Display> fmt::Display for UnitQuaternion<N> {
     }
 }
 
-impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for UnitQuaternion<N> {
+impl<N: Real + AbsDiffEq<Epsilon = N>> AbsDiffEq for UnitQuaternion<N> {
     type Epsilon = N;
 
     #[inline]
@@ -621,16 +632,18 @@ impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for UnitQuaternion<N> {
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.as_ref().abs_diff_eq(other.as_ref(), epsilon)
+    }
+}
+
+impl<N: Real + RelativeEq<Epsilon = N>> RelativeEq for UnitQuaternion<N> {
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -641,6 +654,13 @@ impl<N: Real + ApproxEq<Epsilon = N>> ApproxEq for UnitQuaternion<N> {
         self.as_ref()
             .relative_eq(other.as_ref(), epsilon, max_relative)
     }
+}
+
+impl<N: Real + UlpsEq<Epsilon = N>> UlpsEq for UnitQuaternion<N> {
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/rotation.rs b/src/geometry/rotation.rs
index b956d093..7d0a9416 100644
--- a/src/geometry/rotation.rs
+++ b/src/geometry/rotation.rs
@@ -1,7 +1,7 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use num::{One, Zero};
-use std::hash;
 use std::fmt;
-use approx::ApproxEq;
+use std::hash;
 
 #[cfg(feature = "serde-serialize")]
 use serde;
@@ -14,9 +14,9 @@ use abomonation::Abomonation;
 
 use alga::general::Real;
 
-use core::{DefaultAllocator, MatrixN, Scalar};
-use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
 use core::allocator::Allocator;
+use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
+use core::{DefaultAllocator, MatrixN, Scalar};
 
 /// A rotation matrix.
 #[repr(C)]
@@ -201,9 +201,9 @@ where
     }
 }
 
-impl<N, D: DimName> ApproxEq for Rotation<N, D>
+impl<N, D: DimName> AbsDiffEq for Rotation<N, D>
 where
-    N: Scalar + ApproxEq,
+    N: Scalar + AbsDiffEq,
     DefaultAllocator: Allocator<N, D, D>,
     N::Epsilon: Copy,
 {
@@ -214,16 +214,23 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.matrix.abs_diff_eq(&other.matrix, epsilon)
+    }
+}
+
+impl<N, D: DimName> RelativeEq for Rotation<N, D>
+where
+    N: Scalar + RelativeEq,
+    DefaultAllocator: Allocator<N, D, D>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -234,6 +241,18 @@ where
         self.matrix
             .relative_eq(&other.matrix, epsilon, max_relative)
     }
+}
+
+impl<N, D: DimName> UlpsEq for Rotation<N, D>
+where
+    N: Scalar + UlpsEq,
+    DefaultAllocator: Allocator<N, D, D>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/similarity.rs b/src/geometry/similarity.rs
index 177be162..ef8fd95d 100644
--- a/src/geometry/similarity.rs
+++ b/src/geometry/similarity.rs
@@ -1,6 +1,6 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use std::fmt;
 use std::hash;
-use approx::ApproxEq;
 
 #[cfg(feature = "serde-serialize")]
 use serde;
@@ -11,26 +11,38 @@ use abomonation::Abomonation;
 use alga::general::{Real, SubsetOf};
 use alga::linear::Rotation;
 
-use core::{DefaultAllocator, MatrixN};
+use core::allocator::Allocator;
 use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
 use core::storage::Owned;
-use core::allocator::Allocator;
+use core::{DefaultAllocator, MatrixN};
 use geometry::{Isometry, Point, Translation};
 
 /// A similarity, i.e., an uniform scaling, followed by a rotation, followed by a translation.
 #[repr(C)]
 #[derive(Debug)]
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "serde-serialize",
-           serde(bound(serialize = "N: serde::Serialize,
+#[cfg_attr(
+    feature = "serde-serialize",
+    serde(
+        bound(
+            serialize = "N: serde::Serialize,
                      R: serde::Serialize,
                      DefaultAllocator: Allocator<N, D>,
-                     Owned<N, D>: serde::Serialize")))]
-#[cfg_attr(feature = "serde-serialize",
-           serde(bound(deserialize = "N: serde::Deserialize<'de>,
+                     Owned<N, D>: serde::Serialize"
+        )
+    )
+)]
+#[cfg_attr(
+    feature = "serde-serialize",
+    serde(
+        bound(
+            deserialize = "N: serde::Deserialize<'de>,
                        R: serde::Deserialize<'de>,
                        DefaultAllocator: Allocator<N, D>,
-                       Owned<N, D>: serde::Deserialize<'de>")))]
+                       Owned<N, D>: serde::Deserialize<'de>"
+        )
+    )
+)]
 pub struct Similarity<N: Real, D: DimName, R>
 where
     DefaultAllocator: Allocator<N, D>,
@@ -276,9 +288,9 @@ where
     }
 }
 
-impl<N: Real, D: DimName, R> ApproxEq for Similarity<N, D, R>
+impl<N: Real, D: DimName, R> AbsDiffEq for Similarity<N, D, R>
 where
-    R: Rotation<Point<N, D>> + ApproxEq<Epsilon = N::Epsilon>,
+    R: Rotation<Point<N, D>> + AbsDiffEq<Epsilon = N::Epsilon>,
     DefaultAllocator: Allocator<N, D>,
     N::Epsilon: Copy,
 {
@@ -289,16 +301,24 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.isometry.abs_diff_eq(&other.isometry, epsilon)
+            && self.scaling.abs_diff_eq(&other.scaling, epsilon)
+    }
+}
+
+impl<N: Real, D: DimName, R> RelativeEq for Similarity<N, D, R>
+where
+    R: Rotation<Point<N, D>> + RelativeEq<Epsilon = N::Epsilon>,
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -311,6 +331,18 @@ where
             && self.scaling
                 .relative_eq(&other.scaling, epsilon, max_relative)
     }
+}
+
+impl<N: Real, D: DimName, R> UlpsEq for Similarity<N, D, R>
+where
+    R: Rotation<Point<N, D>> + UlpsEq<Epsilon = N::Epsilon>,
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/translation.rs b/src/geometry/translation.rs
index 09e3cbfb..e19acbdb 100644
--- a/src/geometry/translation.rs
+++ b/src/geometry/translation.rs
@@ -1,7 +1,7 @@
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use num::{One, Zero};
-use std::hash;
 use std::fmt;
-use approx::ApproxEq;
+use std::hash;
 
 #[cfg(feature = "serde-serialize")]
 use serde;
@@ -11,10 +11,10 @@ use abomonation::Abomonation;
 
 use alga::general::{ClosedNeg, Real};
 
-use core::{DefaultAllocator, MatrixN, Scalar, VectorN};
+use core::allocator::Allocator;
 use core::dimension::{DimName, DimNameAdd, DimNameSum, U1};
 use core::storage::Owned;
-use core::allocator::Allocator;
+use core::{DefaultAllocator, MatrixN, Scalar, VectorN};
 
 /// A translation.
 #[repr(C)]
@@ -167,7 +167,7 @@ where
     }
 }
 
-impl<N: Scalar + ApproxEq, D: DimName> ApproxEq for Translation<N, D>
+impl<N: Scalar + AbsDiffEq, D: DimName> AbsDiffEq for Translation<N, D>
 where
     DefaultAllocator: Allocator<N, D>,
     N::Epsilon: Copy,
@@ -179,16 +179,22 @@ where
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.vector.abs_diff_eq(&other.vector, epsilon)
+    }
+}
+
+impl<N: Scalar + RelativeEq, D: DimName> RelativeEq for Translation<N, D>
+where
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -199,6 +205,17 @@ where
         self.vector
             .relative_eq(&other.vector, epsilon, max_relative)
     }
+}
+
+impl<N: Scalar + UlpsEq, D: DimName> UlpsEq for Translation<N, D>
+where
+    DefaultAllocator: Allocator<N, D>,
+    N::Epsilon: Copy,
+{
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
diff --git a/src/geometry/unit_complex.rs b/src/geometry/unit_complex.rs
index 07c7cdca..2ffe369b 100644
--- a/src/geometry/unit_complex.rs
+++ b/src/geometry/unit_complex.rs
@@ -1,6 +1,6 @@
-use std::fmt;
-use approx::ApproxEq;
+use approx::{AbsDiffEq, RelativeEq, UlpsEq};
 use num_complex::Complex;
+use std::fmt;
 
 use alga::general::Real;
 use core::{Matrix2, Matrix3, Unit, Vector1};
@@ -129,7 +129,7 @@ impl<N: Real + fmt::Display> fmt::Display for UnitComplex<N> {
     }
 }
 
-impl<N: Real> ApproxEq for UnitComplex<N> {
+impl<N: Real> AbsDiffEq for UnitComplex<N> {
     type Epsilon = N;
 
     #[inline]
@@ -137,16 +137,18 @@ impl<N: Real> ApproxEq for UnitComplex<N> {
         N::default_epsilon()
     }
 
+    #[inline]
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.re.abs_diff_eq(&other.re, epsilon) && self.im.abs_diff_eq(&other.im, epsilon)
+    }
+}
+
+impl<N: Real> RelativeEq for UnitComplex<N> {
     #[inline]
     fn default_max_relative() -> Self::Epsilon {
         N::default_max_relative()
     }
 
-    #[inline]
-    fn default_max_ulps() -> u32 {
-        N::default_max_ulps()
-    }
-
     #[inline]
     fn relative_eq(
         &self,
@@ -157,6 +159,13 @@ impl<N: Real> ApproxEq for UnitComplex<N> {
         self.re.relative_eq(&other.re, epsilon, max_relative)
             && self.im.relative_eq(&other.im, epsilon, max_relative)
     }
+}
+
+impl<N: Real> UlpsEq for UnitComplex<N> {
+    #[inline]
+    fn default_max_ulps() -> u32 {
+        N::default_max_ulps()
+    }
 
     #[inline]
     fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {