diff --git a/src/macros.rs b/src/macros.rs
index 091a21e..8934148 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -138,7 +138,7 @@ macro_rules! concatenate {
             }
         }
 
-        impl_from_iterator!($name);
+        $crate::impl_from_iterator!($name);
     };
 }
 
diff --git a/tests/histogram.rs b/tests/histogram.rs
index bc0952e..8e14fe4 100644
--- a/tests/histogram.rs
+++ b/tests/histogram.rs
@@ -1,13 +1,3 @@
-#[macro_use] extern crate average;
-
-
-
-use rand_xoshiro;
-use rand_distr;
-#[cfg(feature = "serde1")]
-#[macro_use] extern crate serde_derive;
-#[cfg(feature = "serde1")]
-extern crate serde_json;
 #[cfg(feature = "serde1")]
 #[macro_use] extern crate serde_big_array;
 
@@ -15,7 +5,7 @@ use core::iter::Iterator;
 use rand::SeedableRng;
 use rand_distr::Distribution;
 
-use average::{Histogram, Merge};
+use average::{Histogram, Merge, define_histogram, assert_almost_eq};
 
 define_histogram!(hist10, 10);
 define_histogram!(hist100, 100);
diff --git a/tests/kurtosis.rs b/tests/kurtosis.rs
index 08fb214..df3c2e0 100644
--- a/tests/kurtosis.rs
+++ b/tests/kurtosis.rs
@@ -1,14 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
-use average::{Kurtosis, Estimate, Merge};
+use average::{Kurtosis, Estimate, Merge, assert_almost_eq};
 
 #[test]
 fn trivial() {
diff --git a/tests/macros.rs b/tests/macros.rs
index 3f0db6a..3b6e14d 100644
--- a/tests/macros.rs
+++ b/tests/macros.rs
@@ -1,10 +1,6 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp))]
 
-#[macro_use] extern crate average;
-
-
-
-use average::{Estimate, Min, Max};
+use average::{Estimate, Min, Max, concatenate};
 
 concatenate!(MinMax, [Min, min], [Max, max]);
 
diff --git a/tests/max.rs b/tests/max.rs
index 17c55c0..49a67d4 100644
--- a/tests/max.rs
+++ b/tests/max.rs
@@ -1,11 +1,5 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
 use average::{Max, Estimate, Merge};
diff --git a/tests/mean.rs b/tests/mean.rs
index 208c19d..b3bc05a 100644
--- a/tests/mean.rs
+++ b/tests/mean.rs
@@ -1,14 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-#[cfg(feature = "serde")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
-use average::{MeanWithError, Estimate, Merge};
+use average::{MeanWithError, Estimate, Merge, assert_almost_eq};
 
 #[test]
 fn trivial() {
diff --git a/tests/min.rs b/tests/min.rs
index ef33172..8996d27 100644
--- a/tests/min.rs
+++ b/tests/min.rs
@@ -1,11 +1,5 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
 use average::{Min, Estimate, Merge};
diff --git a/tests/moments.rs b/tests/moments.rs
index 83d97a4..4e80d2e 100644
--- a/tests/moments.rs
+++ b/tests/moments.rs
@@ -1,14 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
-use average::{Moments4, Merge};
+use average::{Moments4, Merge, assert_almost_eq};
 
 #[test]
 fn trivial() {
diff --git a/tests/proptest.rs b/tests/proptest.rs
index f4b5fbe..3e0b7f9 100644
--- a/tests/proptest.rs
+++ b/tests/proptest.rs
@@ -1,10 +1,7 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
 #[macro_use] extern crate proptest;
 
-
-
 use core::iter::Iterator;
 
 use average::Mean;
diff --git a/tests/quantile.rs b/tests/quantile.rs
index 9f0becb..698ad0e 100644
--- a/tests/quantile.rs
+++ b/tests/quantile.rs
@@ -1,10 +1,5 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
-
 use average::{Estimate, Quantile};
 use quantiles::ckms::CKMS;
 
diff --git a/tests/random.rs b/tests/random.rs
index a082fe3..2a0cce8 100644
--- a/tests/random.rs
+++ b/tests/random.rs
@@ -1,13 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-use rand_distr;
-
 use rand_distr::Distribution;
 
-use average::{Kurtosis, Estimate};
+use average::{Kurtosis, Estimate, assert_almost_eq};
 
 #[test]
 fn normal_distribution() {
diff --git a/tests/skewness.rs b/tests/skewness.rs
index 190dce8..2d693b4 100644
--- a/tests/skewness.rs
+++ b/tests/skewness.rs
@@ -1,14 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
-use average::{Skewness, Estimate, Merge};
+use average::{Skewness, Estimate, Merge, assert_almost_eq};
 
 #[test]
 fn trivial() {
diff --git a/tests/streaming_stats.rs b/tests/streaming_stats.rs
index c8679a8..0179129 100644
--- a/tests/streaming_stats.rs
+++ b/tests/streaming_stats.rs
@@ -1,11 +1,6 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-
-
-use stats;
+use average::assert_almost_eq;
 
 /// Create a random vector by sampling from a normal distribution.
 fn initialize_vec(size: usize) -> Vec<f64> {
diff --git a/tests/weighted_mean.rs b/tests/weighted_mean.rs
index 6ba434a..a705bf6 100644
--- a/tests/weighted_mean.rs
+++ b/tests/weighted_mean.rs
@@ -1,14 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
 
-#[macro_use] extern crate average;
-
-
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
 use core::iter::Iterator;
 
-use average::{WeightedMeanWithError, Merge};
+use average::{WeightedMeanWithError, Merge, assert_almost_eq};
 
 #[test]
 fn trivial() {