diff --git a/examples/client.rs b/examples/client.rs
index c45bc2a..71c6888 100644
--- a/examples/client.rs
+++ b/examples/client.rs
@@ -15,7 +15,7 @@ use std::{env, fs, io};
 fn main() {
     // Send GET request and inspect result, with proper error handling.
     if let Err(e) = run_client() {
-        eprintln!("FAILED: {}", e);
+        eprintln!("FAILED: {e}");
         std::process::exit(1);
     }
 }
@@ -34,7 +34,7 @@ async fn run_client() -> io::Result<()> {
 
     // First parameter is target URL (mandatory).
     let url = match env::args().nth(1) {
-        Some(ref url) => Uri::from_str(url).map_err(|e| error(format!("{}", e)))?,
+        Some(ref url) => Uri::from_str(url).map_err(|e| error(format!("{e}")))?,
         None => {
             println!("Usage: client <url> <ca_store>");
             return Ok(());
@@ -44,8 +44,8 @@ async fn run_client() -> io::Result<()> {
     // Second parameter is custom Root-CA store (optional, defaults to native cert store).
     let mut ca = match env::args().nth(2) {
         Some(ref path) => {
-            let f = fs::File::open(path)
-                .map_err(|e| error(format!("failed to open {}: {}", path, e)))?;
+            let f =
+                fs::File::open(path).map_err(|e| error(format!("failed to open {path}: {e}")))?;
             let rd = io::BufReader::new(f);
             Some(rd)
         }
@@ -86,7 +86,7 @@ async fn run_client() -> io::Result<()> {
         let res = client
             .get(url)
             .await
-            .map_err(|e| error(format!("Could not get: {:?}", e)))?;
+            .map_err(|e| error(format!("Could not get: {e:?}")))?;
         println!("Status:\n{}", res.status());
         println!("Headers:\n{:#?}", res.headers());
 
@@ -94,7 +94,7 @@ async fn run_client() -> io::Result<()> {
             .into_body()
             .collect()
             .await
-            .map_err(|e| error(format!("Could not get body: {:?}", e)))?
+            .map_err(|e| error(format!("Could not get body: {e:?}")))?
             .to_bytes();
         println!("Body:\n{}", String::from_utf8_lossy(&body));
 
diff --git a/examples/server.rs b/examples/server.rs
index 8f7803f..6cbcf45 100644
--- a/examples/server.rs
+++ b/examples/server.rs
@@ -23,7 +23,7 @@ use tokio_rustls::TlsAcceptor;
 fn main() {
     // Serve an echo service over HTTPS, with proper error handling.
     if let Err(e) = run_server() {
-        eprintln!("FAILED: {}", e);
+        eprintln!("FAILED: {e}");
         std::process::exit(1);
     }
 }
@@ -52,7 +52,7 @@ async fn run_server() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     // Load private key.
     let key = load_private_key("examples/sample.rsa")?;
 
-    println!("Starting to serve on https://{}", addr);
+    println!("Starting to serve on https://{addr}");
 
     // Create a TCP listener via tokio.
     let incoming = TcpListener::bind(&addr).await?;
@@ -118,8 +118,8 @@ async fn echo(req: Request<Incoming>) -> Result<Response<Full<Bytes>>, hyper::Er
 // Load public certificate from file.
 fn load_certs(filename: &str) -> io::Result<Vec<CertificateDer<'static>>> {
     // Open certificate file.
-    let certfile = fs::File::open(filename)
-        .map_err(|e| error(format!("failed to open {}: {}", filename, e)))?;
+    let certfile =
+        fs::File::open(filename).map_err(|e| error(format!("failed to open {filename}: {e}")))?;
     let mut reader = io::BufReader::new(certfile);
 
     // Load and return certificate.
@@ -129,8 +129,8 @@ fn load_certs(filename: &str) -> io::Result<Vec<CertificateDer<'static>>> {
 // Load private key from file.
 fn load_private_key(filename: &str) -> io::Result<PrivateKeyDer<'static>> {
     // Open keyfile.
-    let keyfile = fs::File::open(filename)
-        .map_err(|e| error(format!("failed to open {}: {}", filename, e)))?;
+    let keyfile =
+        fs::File::open(filename).map_err(|e| error(format!("failed to open {filename}: {e}")))?;
     let mut reader = io::BufReader::new(keyfile);
 
     // Load and return a single private key.
diff --git a/src/config.rs b/src/config.rs
index 3838261..db911b7 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -93,16 +93,14 @@ impl ConfigBuilderExt for ConfigBuilder<ClientConfig, WantsVerifier> {
             match roots.add(cert) {
                 Ok(_) => valid_count += 1,
                 Err(err) => {
-                    crate::log::debug!("certificate parsing failed: {:?}", err);
+                    crate::log::debug!("certificate parsing failed: {err:?}");
                     invalid_count += 1
                 }
             }
         }
 
         crate::log::debug!(
-            "with_native_roots processed {} valid and {} invalid certs",
-            valid_count,
-            invalid_count
+            "with_native_roots processed {valid_count} valid and {invalid_count} invalid certs"
         );
         if roots.is_empty() {
             crate::log::debug!("no valid native root CA certificates found");
diff --git a/tests/tests.rs b/tests/tests.rs
index 91572bc..9e59038 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -29,7 +29,7 @@ fn wait_for_server(addr: &str) {
         }
         thread::sleep(time::Duration::from_millis(i * 100));
     }
-    panic!("failed to connect to {:?} after 10 tries", addr);
+    panic!("failed to connect to {addr:?} after 10 tries");
 }
 
 #[test]
@@ -55,7 +55,7 @@ fn server() {
     let output = Command::new("curl")
         .arg("--insecure")
         .arg("--http1.0")
-        .arg(format!("https://{}", addr))
+        .arg(format!("https://{addr}"))
         .output()
         .expect("cannot run curl");
 
@@ -87,7 +87,7 @@ fn custom_ca_store() {
     wait_for_server(addr);
 
     let rc = client_command()
-        .arg(format!("https://{}", addr))
+        .arg(format!("https://{addr}"))
         .arg("examples/sample.pem")
         .output()
         .expect("cannot run client example");