diff --git a/Cargo.toml b/Cargo.toml
index 4f074b3..3709b12 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ version = "0.14.3"
 authors = ["Niko Matsakis <niko@alum.mit.edu>"]
 readme = "README.md"
 keywords = ["unification", "union-find"]
+edition = "2021"
 
 [features]
 bench = [ ]
diff --git a/src/snapshot_vec.rs b/src/snapshot_vec.rs
index efde49a..4ed298c 100644
--- a/src/snapshot_vec.rs
+++ b/src/snapshot_vec.rs
@@ -26,7 +26,7 @@ use std::marker::PhantomData;
 use std::mem;
 use std::ops;
 
-use undo_log::{Rollback, Snapshots, UndoLogs, VecLog};
+use crate::undo_log::{Rollback, Snapshots, UndoLogs, VecLog};
 
 #[derive(Debug)]
 pub enum UndoLog<D: SnapshotVecDelegate> {
@@ -132,7 +132,7 @@ where
 }
 
 // Snapshots are tokens that should be created/consumed linearly.
-pub struct Snapshot<S = ::undo_log::Snapshot> {
+pub struct Snapshot<S = crate::undo_log::Snapshot> {
     pub(crate) value_count: usize,
     snapshot: S,
 }
diff --git a/src/unify/backing_vec.rs b/src/unify/backing_vec.rs
index 7c1eb2c..56e4caf 100644
--- a/src/unify/backing_vec.rs
+++ b/src/unify/backing_vec.rs
@@ -1,10 +1,10 @@
+use crate::snapshot_vec as sv;
 #[cfg(feature = "persistent")]
 use dogged::DVec;
-use snapshot_vec as sv;
 use std::marker::PhantomData;
 use std::ops::{self, Range};
 
-use undo_log::{Rollback, Snapshots, UndoLogs, VecLog};
+use crate::undo_log::{Rollback, Snapshots, UndoLogs, VecLog};
 
 use super::{UnifyKey, UnifyValue, VarValue};
 
diff --git a/src/unify/mod.rs b/src/unify/mod.rs
index 41c9d46..79f5370 100644
--- a/src/unify/mod.rs
+++ b/src/unify/mod.rs
@@ -35,8 +35,8 @@ use std::fmt::Debug;
 use std::marker;
 use std::ops::Range;
 
-use snapshot_vec::{self as sv, UndoLog};
-use undo_log::{UndoLogs, VecLog};
+use crate::snapshot_vec::{self as sv, UndoLog};
+use crate::undo_log::{UndoLogs, VecLog};
 
 mod backing_vec;
 pub use self::backing_vec::{
diff --git a/src/unify/tests.rs b/src/unify/tests.rs
index 5665aba..3817726 100644
--- a/src/unify/tests.rs
+++ b/src/unify/tests.rs
@@ -16,11 +16,11 @@
 extern crate test;
 #[cfg(feature = "bench")]
 use self::test::Bencher;
+use crate::unify::{EqUnifyValue, InPlace, InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
+use crate::unify::{UnificationStore, UnificationTable};
 use std::cmp;
 #[cfg(feature = "persistent")]
 use unify::Persistent;
-use unify::{EqUnifyValue, InPlace, InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
-use unify::{UnificationStore, UnificationTable};
 
 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
 struct UnitKey(u32);