diff --git a/instant-distance-py/Cargo.toml b/instant-distance-py/Cargo.toml
index 5a3e1a9..d431b0d 100644
--- a/instant-distance-py/Cargo.toml
+++ b/instant-distance-py/Cargo.toml
@@ -2,7 +2,8 @@
 name = "instant-distance-py"
 version = "0.3.2"
 authors = ["Dirkjan Ochtman <dirkjan@ochtman.nl>"]
-edition = "2018"
+edition = "2021"
+rust-version = "1.58"
 license = "MIT OR Apache-2.0"
 workspace = ".."
 description = "Fast minimal implementation of HNSW maps for approximate nearest neighbors searches"
diff --git a/instant-distance-py/src/lib.rs b/instant-distance-py/src/lib.rs
index a41907f..bc35090 100644
--- a/instant-distance-py/src/lib.rs
+++ b/instant-distance-py/src/lib.rs
@@ -58,7 +58,7 @@ impl HnswMap {
             bincode::deserialize_from::<_, instant_distance::HnswMap<FloatArray, MapValue>>(
                 BufReader::with_capacity(32 * 1024 * 1024, File::open(fname)?),
             )
-            .map_err(|e| PyValueError::new_err(format!("deserialization error: {:?}", e)))?;
+            .map_err(|e| PyValueError::new_err(format!("deserialization error: {e:?}")))?;
         Ok(Self { inner: hnsw_map })
     }
 
@@ -66,7 +66,7 @@ impl HnswMap {
     fn dump(&self, fname: &str) -> PyResult<()> {
         let f = BufWriter::with_capacity(32 * 1024 * 1024, File::create(fname)?);
         bincode::serialize_into(f, &self.inner)
-            .map_err(|e| PyValueError::new_err(format!("serialization error: {:?}", e)))?;
+            .map_err(|e| PyValueError::new_err(format!("serialization error: {e:?}")))?;
         Ok(())
     }
 
@@ -115,7 +115,7 @@ impl Hnsw {
         let hnsw = bincode::deserialize_from::<_, instant_distance::Hnsw<FloatArray>>(
             BufReader::with_capacity(32 * 1024 * 1024, File::open(fname)?),
         )
-        .map_err(|e| PyValueError::new_err(format!("deserialization error: {:?}", e)))?;
+        .map_err(|e| PyValueError::new_err(format!("deserialization error: {e:?}")))?;
         Ok(Self { inner: hnsw })
     }
 
@@ -123,7 +123,7 @@ impl Hnsw {
     fn dump(&self, fname: &str) -> PyResult<()> {
         let f = BufWriter::with_capacity(32 * 1024 * 1024, File::create(fname)?);
         bincode::serialize_into(f, &self.inner)
-            .map_err(|e| PyValueError::new_err(format!("serialization error: {:?}", e)))?;
+            .map_err(|e| PyValueError::new_err(format!("serialization error: {e:?}")))?;
         Ok(())
     }
 
diff --git a/instant-distance/Cargo.toml b/instant-distance/Cargo.toml
index caeec1a..f316231 100644
--- a/instant-distance/Cargo.toml
+++ b/instant-distance/Cargo.toml
@@ -3,7 +3,8 @@ name = "instant-distance"
 version = "0.6.0"
 license = "MIT OR Apache-2.0"
 authors = ["Dirkjan Ochtman <dirkjan@ochtman.nl>"]
-edition = "2018"
+edition = "2021"
+rust-version = "1.58"
 description = "Fast minimal implementation of HNSW maps for approximate nearest neighbors searches"
 homepage = "https://github.com/InstantDomain/instant-distance"
 repository = "https://github.com/InstantDomain/instant-distance"
diff --git a/instant-distance/tests/all.rs b/instant-distance/tests/all.rs
index 013327f..276f71c 100644
--- a/instant-distance/tests/all.rs
+++ b/instant-distance/tests/all.rs
@@ -16,7 +16,7 @@ fn map() {
     let values = vec!["zero", "one", "two", "three", "four"];
 
     let seed = ThreadRng::default().gen::<u64>();
-    println!("map (seed = {})", seed);
+    println!("map (seed = {seed})");
     let map = Builder::default().seed(seed).build(points, values);
     let mut search = Search::default();
 
@@ -42,15 +42,15 @@ fn map() {
 #[test]
 fn random_heuristic() {
     let (seed, recall) = randomized(Builder::default());
-    println!("heuristic (seed = {}) recall = {}", seed, recall);
-    assert!(recall > 97, "expected at least 98, got {}", recall);
+    println!("heuristic (seed = {seed}) recall = {recall}");
+    assert!(recall > 97, "expected at least 98, got {recall}");
 }
 
 #[test]
 fn random_simple() {
     let (seed, recall) = randomized(Builder::default().select_heuristic(None));
-    println!("simple (seed = {}) recall = {}", seed, recall);
-    assert!(recall > 90, "expected at least 90, got {}", recall);
+    println!("simple (seed = {seed}) recall = {recall}");
+    assert!(recall > 90, "expected at least 90, got {recall}");
 }
 
 fn randomized(builder: Builder) -> (u64, usize) {