diff --git a/Cargo.toml b/Cargo.toml
index 177fdcd..1ffa503 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ name = "average"
 readme = "README.md"
 repository = "https://github.com/vks/average"
 version = "0.10.0"
+edition = "2018"
 
 [features]
 serde1 = ["serde", "serde_derive", "serde-big-array"]
diff --git a/src/lib.rs b/src/lib.rs
index 83e60c7..e495e9c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -108,12 +108,12 @@ mod quantile;
 mod traits;
 #[macro_use] mod histogram;
 
-pub use moments::{Mean, Variance, Skewness, Kurtosis, MeanWithError};
-pub use weighted_mean::{WeightedMean, WeightedMeanWithError};
-pub use minmax::{Min, Max};
-pub use quantile::Quantile;
-pub use traits::{Estimate, Merge, Histogram};
+pub use crate::moments::{Mean, Variance, Skewness, Kurtosis, MeanWithError};
+pub use crate::weighted_mean::{WeightedMean, WeightedMeanWithError};
+pub use crate::minmax::{Min, Max};
+pub use crate::quantile::Quantile;
+pub use crate::traits::{Estimate, Merge, Histogram};
 
 define_histogram!(hist, 10);
-pub use hist::Histogram as Histogram10;
+pub use crate::hist::Histogram as Histogram10;
 define_moments!(Moments4, 4);
diff --git a/tests/histogram.rs b/tests/histogram.rs
index e4a8790..11b6065 100644
--- a/tests/histogram.rs
+++ b/tests/histogram.rs
@@ -20,7 +20,7 @@ use average::{Histogram, Merge};
 define_histogram!(hist10, 10);
 define_histogram!(hist100, 100);
 
-use hist10::Histogram as Histogram10;
+use crate::hist10::Histogram as Histogram10;
 
 #[test]
 fn with_const_width() {
diff --git a/tests/proptest.rs b/tests/proptest.rs
index 4a28e2c..90bb294 100644
--- a/tests/proptest.rs
+++ b/tests/proptest.rs
@@ -9,7 +9,7 @@ use core::iter::Iterator;
 
 use average::Mean;
 use proptest::prelude::*;
-use prop::num::f64;
+use crate::prop::num::f64;
 
 proptest! {
     #![proptest_config(ProptestConfig::with_cases(10000))]