diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6c5e6f..76305e2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,11 @@
-# 1.1
+# 1.1.1
 
 > Mon Sep 22rd 2019
 
-- Yanked.
+- Add support for [Bézier curves](https://en.wikipedia.org/wiki/B%C3%A9zier_curve). This is
+  normally a breaking change so it’s currently disabled by default and available via the
+  `"bezier"` feature-gate.
+- Add `Spline::get`, `Spline::get_mut` and `Spline::replace`.
 
 # 1.0
 
diff --git a/Cargo.toml b/Cargo.toml
index 3dae0ce..d989696 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "splines"
-version = "1.1.0"
+version = "1.1.1"
 license = "BSD-3-Clause"
 authors = ["Dimitri Sabadie <dimitri.sabadie@gmail.com>"]
 description = "Spline interpolation made easy"
diff --git a/src/cgmath.rs b/src/cgmath.rs
index 5d46b4b..d6f2733 100644
--- a/src/cgmath.rs
+++ b/src/cgmath.rs
@@ -2,7 +2,9 @@ use cgmath::{
   BaseFloat, BaseNum, InnerSpace, Quaternion, Vector1, Vector2, Vector3, Vector4, VectorSpace
 };
 
-use crate::interpolate::{Additive, Interpolate, Linear, One, cubic_hermite_def};
+use crate::interpolate::{
+  Additive, Interpolate, Linear, One, cubic_bezier_def, cubic_hermite_def, quadratic_bezier_def
+};
 
 macro_rules! impl_interpolate_vec {
   ($($t:tt)*) => {
@@ -29,6 +31,18 @@ macro_rules! impl_interpolate_vec {
       fn cubic_hermite(x: (Self, T), a: (Self, T), b: (Self, T), y: (Self, T), t: T) -> Self {
         cubic_hermite_def(x, a, b, y, t)
       }
+
+      #[cfg(feature = "bezier")]
+      #[inline(always)]
+      fn quadratic_bezier(a: Self, u: Self, b: Self, t: T) -> Self {
+        quadratic_bezier_def(a, u, b, t)
+      }
+
+      #[cfg(feature = "bezier")]
+      #[inline(always)]
+      fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: T) -> Self {
+        cubic_bezier_def(a, u, v, b, t)
+      }
     }
   }
 }
@@ -61,4 +75,16 @@ where Self: InnerSpace<Scalar = T>, T: Additive + BaseFloat + One {
   fn cubic_hermite(x: (Self, T), a: (Self, T), b: (Self, T), y: (Self, T), t: T) -> Self {
     cubic_hermite_def(x, a, b, y, t)
   }
+
+  #[cfg(feature = "bezier")]
+  #[inline(always)]
+  fn quadratic_bezier(a: Self, u: Self, b: Self, t: T) -> Self {
+    quadratic_bezier_def(a, u, b, t)
+  }
+
+  #[cfg(feature = "bezier")]
+  #[inline(always)]
+  fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: T) -> Self {
+    cubic_bezier_def(a, u, v, b, t)
+  }
 }
diff --git a/src/interpolate.rs b/src/interpolate.rs
index ed4a9ee..1a6242f 100644
--- a/src/interpolate.rs
+++ b/src/interpolate.rs
@@ -59,9 +59,11 @@ pub trait Interpolate<T>: Sized + Copy {
   }
 
   /// Quadratic Bézier interpolation.
+  #[cfg(feature = "bezier")]
   fn quadratic_bezier(a: Self, u: Self, b: Self, t: T) -> Self;
 
   /// Cubic Bézier interpolation.
+  #[cfg(feature = "bezier")]
   fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: T) -> Self;
 }
 
@@ -221,6 +223,7 @@ where V: Linear<T>,
 /// Default implementation of [`Interpolate::quadratic_bezier`].
 ///
 /// `V` is the value being interpolated. `T` is the sampling value (also sometimes called time).
+#[cfg(feature = "bezier")]
 pub fn quadratic_bezier_def<V, T>(a: V, u: V, b: V, t: T) -> V
 where V: Linear<T>,
       T: Additive + Mul<T, Output = T> + One {
@@ -232,6 +235,7 @@ where V: Linear<T>,
 /// Default implementation of [`Interpolate::cubic_bezier`].
 ///
 /// `V` is the value being interpolated. `T` is the sampling value (also sometimes called time).
+#[cfg(feature = "bezier")]
 pub fn cubic_bezier_def<V, T>(a: V, u: V, v: V, b: V, t: T) -> V
 where V: Linear<T>,
       T: Additive + Mul<T, Output = T> + One {
@@ -254,10 +258,12 @@ macro_rules! impl_interpolate_simple {
         cubic_hermite_def(x, a, b, y, t)
       }
 
+      #[cfg(feature = "bezier")]
       fn quadratic_bezier(a: Self, u: Self, b: Self, t: $t) -> Self {
         quadratic_bezier_def(a, u, b, t)
       }
 
+      #[cfg(feature = "bezier")]
       fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: $t) -> Self {
         cubic_bezier_def(a, u, v, b, t)
       }
@@ -268,27 +274,29 @@ macro_rules! impl_interpolate_simple {
 impl_interpolate_simple!(f32);
 impl_interpolate_simple!(f64);
 
-//macro_rules! impl_interpolate_via {
-//  ($t:ty, $v:ty) => {
-//    impl Interpolate<$t> for $v {
-//      fn lerp(a: Self, b: Self, t: $t) -> Self {
-//        a * (1. - t as $v) + b * t as $v
-//      }
-//
-//      fn cubic_hermite((x, xt): (Self, $t), (a, at): (Self, $t), (b, bt): (Self, $t), (y, yt): (Self, $t), t: $t) -> Self {
-//        cubic_hermite_def((x, xt as $v), (a, at as $v), (b, bt as $v), (y, yt as $v), t as $v)
-//      }
-//
-//      fn quadratic_bezier(a: Self, u: Self, b: Self, t: $t) -> Self {
-//        $t::quadratic_bezier(a as $t, u as $t, b as $t, t)
-//      }
-//
-//      fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: $t) -> Self {
-//        $t::cubic_bezier(a as $t, u as $t, v as $t, b as $t, t)
-//      }
-//    }
-//  }
-//}
-//
-//impl_interpolate_via!(f32, f64);
-//impl_interpolate_via!(f64, f32);
+macro_rules! impl_interpolate_via {
+  ($t:ty, $v:ty) => {
+    impl Interpolate<$t> for $v {
+      fn lerp(a: Self, b: Self, t: $t) -> Self {
+        a * (1. - t as $v) + b * t as $v
+      }
+
+      fn cubic_hermite((x, xt): (Self, $t), (a, at): (Self, $t), (b, bt): (Self, $t), (y, yt): (Self, $t), t: $t) -> Self {
+        cubic_hermite_def((x, xt as $v), (a, at as $v), (b, bt as $v), (y, yt as $v), t as $v)
+      }
+
+      #[cfg(feature = "bezier")]
+      fn quadratic_bezier(a: Self, u: Self, b: Self, t: $t) -> Self {
+        quadratic_bezier_def(a, u, b, t as $v)
+      }
+
+      #[cfg(feature = "bezier")]
+      fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: $t) -> Self {
+        cubic_bezier_def(a, u, v, b, t as $v)
+      }
+    }
+  }
+}
+
+impl_interpolate_via!(f32, f64);
+impl_interpolate_via!(f64, f32);
diff --git a/src/interpolation.rs b/src/interpolation.rs
index b02022e..7974832 100644
--- a/src/interpolation.rs
+++ b/src/interpolation.rs
@@ -5,11 +5,12 @@
 /// Available kind of interpolations.
 ///
 /// Feel free to visit each variant for more documentation.
+#[cfg(feature = "bezier")]
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "serialization", derive(Deserialize, Serialize))]
 #[cfg_attr(feature = "serialization", serde(rename_all = "snake_case"))]
 pub enum Interpolation<T, V> {
-  /// Hold a [`Key<T, _>`] until the sampling value passes the normalized step threshold, in which
+  /// Hold a [`Key`] until the sampling value passes the normalized step threshold, in which
   /// case the next key is used.
   ///
   /// > Note: if you set the threshold to `0.5`, the first key will be used until half the time
@@ -17,7 +18,7 @@ pub enum Interpolation<T, V> {
   /// > first key will be kept until the next key. Set it to `0.` and the first key will never be
   /// > used.
   ///
-  /// [`Key<T, _>`]: crate::key::Key
+  /// [`Key`]: crate::key::Key
   Step(T),
   /// Linear interpolation between a key and the next one.
   Linear,
@@ -41,11 +42,35 @@ pub enum Interpolation<T, V> {
   ///   interpolation_ and it kicks ass too, but a bit less than cubic.
   #[cfg(feature = "bezier")]
   Bezier(V),
-  #[cfg(not(any(feature = "bezier")))]
-  #[doc(hidden)]
-  _V(std::marker::PhantomData<V>),
 }
 
+/// Available kind of interpolations.
+///
+/// Feel free to visit each variant for more documentation.
+#[cfg(not(feature = "bezier"))]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serialization", derive(Deserialize, Serialize))]
+#[cfg_attr(feature = "serialization", serde(rename_all = "snake_case"))]
+pub enum Interpolation<T> {
+  /// Hold a [`Key`] until the sampling value passes the normalized step threshold, in which
+  /// case the next key is used.
+  ///
+  /// > Note: if you set the threshold to `0.5`, the first key will be used until half the time
+  /// > between the two keys; the second key will be in used afterwards. If you set it to `1.0`, the
+  /// > first key will be kept until the next key. Set it to `0.` and the first key will never be
+  /// > used.
+  ///
+  /// [`Key`]: crate::key::Key
+  Step(T),
+  /// Linear interpolation between a key and the next one.
+  Linear,
+  /// Cosine interpolation between a key and the next one.
+  Cosine,
+  /// Catmull-Rom interpolation, performing a cubic Hermite interpolation using four keys.
+  CatmullRom,
+}
+
+#[cfg(feature = "bezier")]
 impl<T, V> Default for Interpolation<T, V> {
   /// [`Interpolation::Linear`] is the default.
   fn default() -> Self {
@@ -53,3 +78,10 @@ impl<T, V> Default for Interpolation<T, V> {
   }
 }
 
+#[cfg(not(feature = "bezier"))]
+impl<T> Default for Interpolation<T> {
+  /// [`Interpolation::Linear`] is the default.
+  fn default() -> Self {
+    Interpolation::Linear
+  }
+}
diff --git a/src/key.rs b/src/key.rs
index 76f09f6..983ee76 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -17,6 +17,7 @@ use crate::interpolation::Interpolation;
 /// key and the next one – if existing. Have a look at [`Interpolation`] for further details.
 ///
 /// [`Interpolation`]: crate::interpolation::Interpolation
+#[cfg(feature = "bezier")]
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "serialization", derive(Deserialize, Serialize))]
 #[cfg_attr(feature = "serialization", serde(rename_all = "snake_case"))]
@@ -29,9 +30,36 @@ pub struct Key<T, V> {
   pub interpolation: Interpolation<T, V>
 }
 
+/// A spline control point.
+///
+/// This type associates a value at a given interpolation parameter value. It also contains an
+/// interpolation mode used to determine how to interpolate values on the segment defined by this
+/// key and the next one – if existing. Have a look at [`Interpolation`] for further details.
+///
+/// [`Interpolation`]: crate::interpolation::Interpolation
+#[cfg(not(feature = "bezier"))]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "serialization", derive(Deserialize, Serialize))]
+#[cfg_attr(feature = "serialization", serde(rename_all = "snake_case"))]
+pub struct Key<T, V> {
+  /// Interpolation parameter at which the [`Key`] should be reached.
+  pub t: T,
+  /// Carried value.
+  pub value: V,
+  /// Interpolation mode.
+  pub interpolation: Interpolation<T>
+}
+
 impl<T, V> Key<T, V> {
   /// Create a new key.
+  #[cfg(feature = "bezier")]
   pub fn new(t: T, value: V, interpolation: Interpolation<T, V>) -> Self {
     Key { t, value, interpolation }
   }
+
+  /// Create a new key.
+  #[cfg(not(feature = "bezier"))]
+  pub fn new(t: T, value: V, interpolation: Interpolation<T>) -> Self {
+    Key { t, value, interpolation }
+  }
 }
diff --git a/src/nalgebra.rs b/src/nalgebra.rs
index c13f4c7..ccb261f 100644
--- a/src/nalgebra.rs
+++ b/src/nalgebra.rs
@@ -3,7 +3,9 @@ use nalgebra::{Scalar, Vector, Vector1, Vector2, Vector3, Vector4, Vector5, Vect
 use num_traits as nt;
 use std::ops::Mul;
 
-use crate::interpolate::{Interpolate, Linear, Additive, One, cubic_hermite_def};
+use crate::interpolate::{
+  Interpolate, Linear, Additive, One, cubic_bezier_def, cubic_hermite_def, quadratic_bezier_def
+};
 
 macro_rules! impl_interpolate_vector {
   ($($t:tt)*) => {
@@ -40,6 +42,18 @@ macro_rules! impl_interpolate_vector {
       fn cubic_hermite(x: (Self, T), a: (Self, T), b: (Self, T), y: (Self, T), t: T) -> Self {
         cubic_hermite_def(x, a, b, y, t)
       }
+
+      #[cfg(feature = "bezier")]
+      #[inline(always)]
+      fn quadratic_bezier(a: Self, u: Self, b: Self, t: T) -> Self {
+        quadratic_bezier_def(a, u, b, t)
+      }
+
+      #[cfg(feature = "bezier")]
+      #[inline(always)]
+      fn cubic_bezier(a: Self, u: Self, v: Self, b: Self, t: T) -> Self {
+        cubic_bezier_def(a, u, v, b, t)
+      }
     }
   }
 }
diff --git a/src/spline.rs b/src/spline.rs
index 1e20e95..ac0ed72 100644
--- a/src/spline.rs
+++ b/src/spline.rs
@@ -146,9 +146,6 @@ impl<T, V> Spline<T, V> {
           Some(Interpolate::quadratic_bezier(cp0.value, u, cp1.value, nt))
         }
       }
-
-      #[cfg(not(any(feature = "bezier")))]
-      Interpolation::_V(_) => unreachable!()
     }
   }
 
@@ -199,6 +196,57 @@ impl<T, V> Spline<T, V> {
       Some(self.0.remove(index))
     }
   }
+
+  /// Update a key and return the key already present.
+  ///
+  /// The key is updated — if present — with the provided function.
+  ///
+  /// # Notes
+  ///
+  /// That function makes sense only if you want to change the interpolator (i.e. [`Key::t`]) of
+  /// your key. If you just want to change the interpolation mode or the carried value, consider
+  /// using the [`Spline::get_mut`] method instead as it will be way faster.
+  pub fn replace<F>(
+    &mut self,
+    index: usize,
+    f: F
+  ) -> Option<Key<T, V>>
+  where
+    F: FnOnce(&Key<T, V>) -> Key<T, V>,
+    T: PartialOrd
+  {
+    let key = self.remove(index)?;
+    self.add(f(&key));
+    Some(key)
+  }
+
+  /// Get a key at a given index.
+  pub fn get(&self, index: usize) -> Option<&Key<T, V>> {
+    self.0.get(index)
+  }
+
+  /// Mutably get a key at a given index.
+  pub fn get_mut(&mut self, index: usize) -> Option<KeyMut<T, V>> {
+    self.0.get_mut(index).map(|key| KeyMut {
+      value: &mut key.value,
+      interpolation: &mut key.interpolation
+    })
+  }
+}
+
+/// A mutable [`Key`].
+///
+/// Mutable keys allow to edit the carried values and the interpolation mode but not the actual
+/// interpolator value as it would invalidate the internal structure of the [`Spline`]. If you
+/// want to achieve this, you’re advised to use [`Spline::replace`].
+pub struct KeyMut<'a, T, V> {
+  /// Carried value.
+  pub value: &'a mut V,
+  /// Interpolation mode to use for that key.
+  #[cfg(feature = "bezier")]
+  pub interpolation: &'a mut Interpolation<T, V>,
+  #[cfg(not(feature = "bezier"))]
+  pub interpolation: &'a mut Interpolation<T>,
 }
 
 // Normalize a time ([0;1]) given two control points.