diff --git a/benches/lib.rs b/benches/lib.rs
index 377cd04f..6ca7e830 100644
--- a/benches/lib.rs
+++ b/benches/lib.rs
@@ -2,9 +2,6 @@
 #![allow(unused_macros)]
 
 extern crate nalgebra as na;
-extern crate rand;
-extern crate test;
-extern crate typenum;
 
 #[macro_use]
 extern crate criterion;
@@ -35,4 +32,4 @@ criterion_main!(
     linalg::solve,
     linalg::svd,
     linalg::symmetric_eigen,
-);
\ No newline at end of file
+);
diff --git a/examples/dimensional_genericity.rs b/examples/dimensional_genericity.rs
index 411a0666..1d96ca74 100644
--- a/examples/dimensional_genericity.rs
+++ b/examples/dimensional_genericity.rs
@@ -1,4 +1,3 @@
-extern crate alga;
 extern crate nalgebra as na;
 
 use alga::linear::FiniteDimInnerSpace;
diff --git a/examples/identity.rs b/examples/identity.rs
index c20c5616..00f0ec6f 100644
--- a/examples/identity.rs
+++ b/examples/identity.rs
@@ -1,4 +1,3 @@
-extern crate alga;
 extern crate nalgebra as na;
 
 use alga::linear::Transformation;
@@ -36,4 +35,4 @@ fn main() {
     // They both return the same result.
     assert!(result1 == Vector3::new(100001.0, 200002.0, 300003.0));
     assert!(result2 == Vector3::new(100001.0, 200002.0, 300003.0));
-}
\ No newline at end of file
+}
diff --git a/examples/scalar_genericity.rs b/examples/scalar_genericity.rs
index 75f6f9d4..5ef89248 100644
--- a/examples/scalar_genericity.rs
+++ b/examples/scalar_genericity.rs
@@ -1,4 +1,3 @@
-extern crate alga;
 extern crate nalgebra as na;
 
 use alga::general::{RealField, RingCommutative};
diff --git a/examples/transform_matrix4.rs b/examples/transform_matrix4.rs
index a9e6cd6e..74649d74 100644
--- a/examples/transform_matrix4.rs
+++ b/examples/transform_matrix4.rs
@@ -1,4 +1,3 @@
-extern crate alga;
 #[macro_use]
 extern crate approx;
 extern crate nalgebra as na;
diff --git a/examples/transform_vector_point3.rs b/examples/transform_vector_point3.rs
index 57a189cc..cf2921a5 100644
--- a/examples/transform_vector_point3.rs
+++ b/examples/transform_vector_point3.rs
@@ -1,4 +1,3 @@
-extern crate alga;
 extern crate nalgebra as na;
 
 use na::{Matrix4, Point3, Vector3, Vector4};
diff --git a/nalgebra-glm/src/lib.rs b/nalgebra-glm/src/lib.rs
index c8f266a4..fe3a32a0 100644
--- a/nalgebra-glm/src/lib.rs
+++ b/nalgebra-glm/src/lib.rs
@@ -116,7 +116,6 @@
 extern crate num_traits as num;
 #[macro_use]
 extern crate approx;
-extern crate alga;
 extern crate nalgebra as na;
 
 pub use crate::aliases::*;
diff --git a/nalgebra-lapack/benches/lib.rs b/nalgebra-lapack/benches/lib.rs
index 141e65d9..3b23d259 100644
--- a/nalgebra-lapack/benches/lib.rs
+++ b/nalgebra-lapack/benches/lib.rs
@@ -2,7 +2,5 @@
 
 extern crate nalgebra as na;
 extern crate nalgebra_lapack as nl;
-extern crate rand;
-extern crate test;
 
 mod linalg;
diff --git a/nalgebra-lapack/src/lib.rs b/nalgebra-lapack/src/lib.rs
index d58aba0b..39965a59 100644
--- a/nalgebra-lapack/src/lib.rs
+++ b/nalgebra-lapack/src/lib.rs
@@ -73,11 +73,7 @@
     html_root_url = "https://nalgebra.org/rustdoc"
 )]
 
-extern crate alga;
-extern crate lapack;
-extern crate lapack_src;
 extern crate nalgebra as na;
-extern crate num_complex;
 extern crate num_traits as num;
 
 mod lapack_check;
diff --git a/src/base/blas.rs b/src/base/blas.rs
index cc8f2345..ded53f7f 100644
--- a/src/base/blas.rs
+++ b/src/base/blas.rs
@@ -21,8 +21,6 @@ impl<N: ComplexField, D: Dim, S: Storage<N, D>> Vector<N, D, S> {
     /// # Examples:
     ///
     /// ```
-    /// # extern crate num_complex;
-    /// # extern crate nalgebra;
     /// # use num_complex::Complex;
     /// # use nalgebra::Vector3;
     /// let vec = Vector3::new(Complex::new(11.0, 3.0), Complex::new(-15.0, 0.0), Complex::new(13.0, 5.0));
diff --git a/src/geometry/unit_complex.rs b/src/geometry/unit_complex.rs
index 7ba7f374..434355de 100755
--- a/src/geometry/unit_complex.rs
+++ b/src/geometry/unit_complex.rs
@@ -84,7 +84,6 @@ impl<N: RealField> UnitComplex<N> {
     ///
     /// # Example
     /// ```
-    /// # extern crate num_complex;
     /// # use num_complex::Complex;
     /// # use nalgebra::UnitComplex;
     /// let angle = 1.78f32;
@@ -373,4 +372,4 @@ impl<N: RealField> UlpsEq for UnitComplex<N> {
         self.re.ulps_eq(&other.re, epsilon, max_ulps)
             && self.im.ulps_eq(&other.im, epsilon, max_ulps)
     }
-}
\ No newline at end of file
+}
diff --git a/src/lib.rs b/src/lib.rs
index a62577c1..59f3420f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -89,32 +89,13 @@ an optimized set of tools for computer graphics and physics. Those features incl
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(all(feature = "alloc", not(feature = "std")), feature(alloc))]
 
-#[cfg(feature = "arbitrary")]
-extern crate quickcheck;
-
-#[cfg(feature = "serde")]
-extern crate serde;
 #[cfg(feature = "serde")]
 #[macro_use]
 extern crate serde_derive;
 
-#[cfg(feature = "abomonation-serialize")]
-extern crate abomonation;
-
-#[cfg(feature = "mint")]
-extern crate mint;
-
 #[macro_use]
 extern crate approx;
-extern crate generic_array;
-#[cfg(feature = "std")]
-extern crate matrixmultiply;
-extern crate num_complex;
 extern crate num_traits as num;
-extern crate num_rational;
-extern crate typenum;
-
-extern crate alga;
 
 #[cfg(all(feature = "alloc", not(feature = "std")))]
 extern crate alloc;
@@ -122,8 +103,6 @@ extern crate alloc;
 #[cfg(not(feature = "std"))]
 extern crate core as std;
 
-#[cfg(feature = "io")]
-extern crate pest;
 #[macro_use]
 #[cfg(feature = "io")]
 extern crate pest_derive;
diff --git a/tests/lib.rs b/tests/lib.rs
index f6634d0f..4aa95744 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -1,18 +1,10 @@
-#[cfg(feature = "abomonation-serialize")]
-extern crate abomonation;
-extern crate alga;
 #[macro_use]
 extern crate approx;
-#[cfg(feature = "mint")]
-extern crate mint;
 extern crate nalgebra as na;
 extern crate num_traits as num;
 #[cfg(feature = "arbitrary")]
 #[macro_use]
 extern crate quickcheck;
-extern crate rand;
-extern crate serde_json;
-extern crate num_complex;
 
 mod core;
 mod geometry;