diff --git a/Cargo.toml b/Cargo.toml
index 1154c73..3cf3cfb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 name = "rust_hanabi"
 version = "0.1.0"
 authors = ["Jeff Wu <wuthefwasthat@gmail.com>"]
+edition = "2021"
 
 [dependencies]
 rand = "0.3.0"
diff --git a/src/helpers.rs b/src/helpers.rs
index 800756e..9f9e946 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -6,7 +6,7 @@ use std::hash::Hash;
 use std::ops::{Index, IndexMut};
 use std::slice;
 
-use game::*;
+use crate::game::*;
 
 // trait representing information about a card
 pub trait CardInfo {
diff --git a/src/main.rs b/src/main.rs
index 69e03ed..0caef30 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -236,7 +236,7 @@ fn get_results_table() -> String {
     }
     fn concat_twolines(body: Vec<TwoLines>) -> String {
         body.into_iter().fold(String::default(), |output, (a, b)| {
-            (output + &a + "\n" + &b + "\n")
+            output + &a + "\n" + &b + "\n"
         })
     }
     let header = make_twolines(&player_nums, (space.clone(), dashes), &|n_players| {
diff --git a/src/simulator.rs b/src/simulator.rs
index fdcd105..884103b 100644
--- a/src/simulator.rs
+++ b/src/simulator.rs
@@ -1,10 +1,9 @@
-use crossbeam;
 use fnv::FnvHashMap;
 use rand::{self, Rng, SeedableRng};
 use std::fmt;
 
-use game::*;
-use strategy::*;
+use crate::game::*;
+use crate::strategy::*;
 
 fn new_deck(seed: u32) -> Cards {
     let mut deck: Cards = Cards::new();
diff --git a/src/strategies/cheating.rs b/src/strategies/cheating.rs
index 00a4da2..fe24cd2 100644
--- a/src/strategies/cheating.rs
+++ b/src/strategies/cheating.rs
@@ -2,8 +2,8 @@ use fnv::{FnvHashMap, FnvHashSet};
 use std::cell::RefCell;
 use std::rc::Rc;
 
-use game::*;
-use strategy::*;
+use crate::game::*;
+use crate::strategy::*;
 
 // strategy that explicitly cheats by using Rc/RefCell
 // serves as a reference point for other strategies
diff --git a/src/strategies/examples.rs b/src/strategies/examples.rs
index 5b5f15f..a944a50 100644
--- a/src/strategies/examples.rs
+++ b/src/strategies/examples.rs
@@ -1,6 +1,6 @@
-use game::*;
+use crate::game::*;
+use crate::strategy::*;
 use rand::{self, Rng};
-use strategy::*;
 
 // dummy, terrible strategy, as an example
 #[derive(Clone)]
diff --git a/src/strategies/hat_helpers.rs b/src/strategies/hat_helpers.rs
index f4d94e0..bc01152 100644
--- a/src/strategies/hat_helpers.rs
+++ b/src/strategies/hat_helpers.rs
@@ -1,5 +1,5 @@
-use game::*;
-use helpers::*;
+use crate::game::*;
+use crate::helpers::*;
 
 #[derive(Debug, Clone)]
 pub struct ModulusInformation {
diff --git a/src/strategies/information.rs b/src/strategies/information.rs
index baea99a..f2da8f5 100644
--- a/src/strategies/information.rs
+++ b/src/strategies/information.rs
@@ -2,10 +2,10 @@ use float_ord::*;
 use fnv::{FnvHashMap, FnvHashSet};
 use std::cmp::Ordering;
 
-use game::*;
-use helpers::*;
-use strategies::hat_helpers::*;
-use strategy::*;
+use crate::game::*;
+use crate::helpers::*;
+use crate::strategies::hat_helpers::*;
+use crate::strategy::*;
 
 // TODO: use random extra information - i.e. when casting up and down,
 // we sometimes have 2 choices of value to choose
diff --git a/src/strategy.rs b/src/strategy.rs
index eade9b8..f688379 100644
--- a/src/strategy.rs
+++ b/src/strategy.rs
@@ -1,4 +1,4 @@
-use game::*;
+use crate::game::*;
 
 // Traits to implement for any valid Hanabi strategy