diff --git a/actix-identity/tests/integration/test_app.rs b/actix-identity/tests/integration/test_app.rs
index 9ff493e3f..89ba665ed 100644
--- a/actix-identity/tests/integration/test_app.rs
+++ b/actix-identity/tests/integration/test_app.rs
@@ -32,7 +32,8 @@ impl TestApp {
         .listen(listener)
         .unwrap()
         .run();
-        let _ = actix_web::rt::spawn(server);
+
+        actix_web::rt::spawn(server);
 
         let client = reqwest::Client::builder()
             .cookie_store(true)
diff --git a/actix-limitation/tests/tests.rs b/actix-limitation/tests/tests.rs
index 07df6eb1a..fa6f1ae1d 100644
--- a/actix-limitation/tests/tests.rs
+++ b/actix-limitation/tests/tests.rs
@@ -21,7 +21,7 @@ async fn test_limiter_count() -> Result<(), Error> {
 
     for i in 0..20 {
         let status = limiter.count(id.to_string()).await?;
-        println!("status: {:?}", status);
+        println!("status: {status:?}");
         assert_eq!(20 - status.remaining(), i + 1);
     }
 
diff --git a/actix-protobuf/src/lib.rs b/actix-protobuf/src/lib.rs
index 743a51d56..f2f7e0160 100644
--- a/actix-protobuf/src/lib.rs
+++ b/actix-protobuf/src/lib.rs
@@ -39,15 +39,15 @@ pub enum ProtoBufPayloadError {
     ContentType,
 
     /// Serialize error
-    #[display(fmt = "ProtoBuf serialize error: {}", _0)]
+    #[display(fmt = "ProtoBuf serialize error: {_0}")]
     Serialize(ProtoBufEncodeError),
 
     /// Deserialize error
-    #[display(fmt = "ProtoBuf deserialize error: {}", _0)]
+    #[display(fmt = "ProtoBuf deserialize error: {_0}")]
     Deserialize(ProtoBufDecodeError),
 
     /// Payload error
-    #[display(fmt = "Error that occur during reading payload: {}", _0)]
+    #[display(fmt = "Error that occur during reading payload: {_0}")]
     Payload(PayloadError),
 }
 
diff --git a/actix-redis/src/lib.rs b/actix-redis/src/lib.rs
index e7cd980c8..6d0ca7c40 100644
--- a/actix-redis/src/lib.rs
+++ b/actix-redis/src/lib.rs
@@ -13,7 +13,7 @@ pub use self::redis::{Command, RedisActor};
 /// General purpose `actix-redis` error.
 #[derive(Debug, Display, Error, From)]
 pub enum Error {
-    #[display(fmt = "Redis error: {}", _0)]
+    #[display(fmt = "Redis error: {_0}")]
     Redis(redis_async::error::Error),
 
     /// Receiving message during reconnecting.
diff --git a/actix-redis/tests/test_redis.rs b/actix-redis/tests/test_redis.rs
index 6ae83f1e1..fa2f88f26 100644
--- a/actix-redis/tests/test_redis.rs
+++ b/actix-redis/tests/test_redis.rs
@@ -31,7 +31,7 @@ async fn test_redis() {
             let res = addr.send(Command(resp_array!["GET", "test"])).await;
             match res {
                 Ok(Ok(resp)) => {
-                    println!("RESP: {:?}", resp);
+                    println!("RESP: {resp:?}");
                     assert_eq!(resp, RespValue::BulkString((&b"value"[..]).into()));
                 }
                 _ => panic!("Should not happen {:?}", res),
diff --git a/actix-session/examples/basic.rs b/actix-session/examples/basic.rs
index 3f41c68dc..f1f08ae66 100644
--- a/actix-session/examples/basic.rs
+++ b/actix-session/examples/basic.rs
@@ -3,11 +3,11 @@ use actix_web::{cookie::Key, middleware, web, App, Error, HttpRequest, HttpServe
 
 /// simple handler
 async fn index(req: HttpRequest, session: Session) -> Result<impl Responder, Error> {
-    println!("{:?}", req);
+    println!("{req:?}");
 
     // session
     if let Some(count) = session.get::<i32>("counter")? {
-        println!("SESSION value: {}", count);
+        println!("SESSION value: {count}");
         session.insert("counter", count + 1)?;
     } else {
         session.insert("counter", 1)?;
diff --git a/actix-session/src/lib.rs b/actix-session/src/lib.rs
index 0a8d5587f..6c6615ef6 100644
--- a/actix-session/src/lib.rs
+++ b/actix-session/src/lib.rs
@@ -179,7 +179,7 @@ pub mod test_helpers {
             CookieContentSecurity::Signed,
             CookieContentSecurity::Private,
         ] {
-            println!("Using {:?} as cookie content security policy.", policy);
+            println!("Using {policy:?} as cookie content security policy.");
             acceptance_tests::basic_workflow(store_builder.clone(), *policy).await;
             acceptance_tests::expiration_is_refreshed_on_changes(store_builder.clone(), *policy)
                 .await;
@@ -243,7 +243,7 @@ pub mod test_helpers {
                     }))
                     .service(web::resource("/test/").to(|ses: Session| async move {
                         let val: usize = ses.get("counter").unwrap().unwrap();
-                        format!("counter: {}", val)
+                        format!("counter: {val}")
                     })),
             )
             .await;
@@ -710,9 +710,9 @@ pub mod test_helpers {
         async fn logout(session: Session) -> Result<HttpResponse> {
             let id: Option<String> = session.get("user_id")?;
 
-            let body = if let Some(x) = id {
+            let body = if let Some(id) = id {
                 session.purge();
-                format!("Logged out: {}", x)
+                format!("Logged out: {id}")
             } else {
                 "Could not log out anonymous user".to_owned()
             };
diff --git a/actix-session/src/session.rs b/actix-session/src/session.rs
index 35aaaa3f2..3a056e1ba 100644
--- a/actix-session/src/session.rs
+++ b/actix-session/src/session.rs
@@ -291,7 +291,7 @@ impl FromRequest for Session {
 
 /// Error returned by [`Session::get`].
 #[derive(Debug, Display, From)]
-#[display(fmt = "{}", _0)]
+#[display(fmt = "{_0}")]
 pub struct SessionGetError(anyhow::Error);
 
 impl StdError for SessionGetError {
@@ -308,7 +308,7 @@ impl ResponseError for SessionGetError {
 
 /// Error returned by [`Session::insert`].
 #[derive(Debug, Display, From)]
-#[display(fmt = "{}", _0)]
+#[display(fmt = "{_0}")]
 pub struct SessionInsertError(anyhow::Error);
 
 impl StdError for SessionInsertError {
diff --git a/actix-settings/src/error.rs b/actix-settings/src/error.rs
index f3834cf45..f59e355f0 100644
--- a/actix-settings/src/error.rs
+++ b/actix-settings/src/error.rs
@@ -89,7 +89,7 @@ impl From<Error> for io::Error {
     fn from(err: Error) -> Self {
         match err {
             Error::EnvVarError(var_error) => {
-                let msg = format!("Env var error: {}", var_error);
+                let msg = format!("Env var error: {var_error}");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
 
@@ -105,32 +105,29 @@ impl From<Error> for io::Error {
                 line,
                 column,
             } => {
-                let msg = format!(
-                    "Expected {}, got {}  (@ {}:{}:{})",
-                    expected, got, file, line, column
-                );
+                let msg = format!("Expected {expected}, got {got}  (@ {file}:{line}:{column})");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
 
             Error::IoError(io_error) => io_error.into(),
 
             Error::ParseBoolError(parse_bool_error) => {
-                let msg = format!("Failed to parse boolean: {}", parse_bool_error);
+                let msg = format!("Failed to parse boolean: {parse_bool_error}");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
 
             Error::ParseIntError(parse_int_error) => {
-                let msg = format!("Failed to parse integer: {}", parse_int_error);
+                let msg = format!("Failed to parse integer: {parse_int_error}");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
 
             Error::ParseAddressError(string) => {
-                let msg = format!("Failed to parse address: {}", string);
+                let msg = format!("Failed to parse address: {string}");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
 
             Error::TomlError(toml_error) => {
-                let msg = format!("TOML error: {}", toml_error);
+                let msg = format!("TOML error: {toml_error}");
                 io::Error::new(io::ErrorKind::InvalidInput, msg)
             }
         }
diff --git a/actix-settings/src/lib.rs b/actix-settings/src/lib.rs
index 8383dc015..a0d0e3024 100644
--- a/actix-settings/src/lib.rs
+++ b/actix-settings/src/lib.rs
@@ -274,7 +274,7 @@ where
             todo!("[ApplySettings] TLS support has not been implemented yet.");
         } else {
             for Address { host, port } in &settings.actix.hosts {
-                self = self.bind(format!("{}:{}", host, port))
+                self = self.bind(format!("{host}:{port}"))
                     .unwrap(/*TODO*/);
             }
         }
diff --git a/actix-web-httpauth/examples/with-cors.rs b/actix-web-httpauth/examples/with-cors.rs
index 4f034a295..a5e37d881 100644
--- a/actix-web-httpauth/examples/with-cors.rs
+++ b/actix-web-httpauth/examples/with-cors.rs
@@ -6,7 +6,7 @@ async fn ok_validator(
     req: ServiceRequest,
     credentials: BearerAuth,
 ) -> Result<ServiceRequest, (Error, ServiceRequest)> {
-    eprintln!("{:?}", credentials);
+    eprintln!("{credentials:?}");
     Ok(req)
 }
 
diff --git a/actix-web-httpauth/src/headers/authorization/errors.rs b/actix-web-httpauth/src/headers/authorization/errors.rs
index a203f6312..465156897 100644
--- a/actix-web-httpauth/src/headers/authorization/errors.rs
+++ b/actix-web-httpauth/src/headers/authorization/errors.rs
@@ -32,7 +32,7 @@ impl fmt::Display for ParseError {
         match self {
             ParseError::Invalid => f.write_str("Invalid header value"),
             ParseError::MissingScheme => f.write_str("Missing authorization scheme"),
-            ParseError::MissingField(field) => write!(f, "Missing header field ({})", field),
+            ParseError::MissingField(field) => write!(f, "Missing header field ({field})"),
             ParseError::ToStrError(err) => fmt::Display::fmt(err, f),
             ParseError::Base64DecodeError(err) => fmt::Display::fmt(err, f),
             ParseError::Utf8Error(err) => fmt::Display::fmt(err, f),
diff --git a/actix-web-httpauth/src/headers/www_authenticate/challenge/bearer/mod.rs b/actix-web-httpauth/src/headers/www_authenticate/challenge/bearer/mod.rs
index f957dedc4..8c180b151 100644
--- a/actix-web-httpauth/src/headers/www_authenticate/challenge/bearer/mod.rs
+++ b/actix-web-httpauth/src/headers/www_authenticate/challenge/bearer/mod.rs
@@ -12,14 +12,14 @@ mod tests {
 
     #[test]
     fn to_bytes() {
-        let b = Bearer::build()
+        let bearer = Bearer::build()
             .error(Error::InvalidToken)
             .error_description("Subject 8740827c-2e0a-447b-9716-d73042e4039d not found")
             .finish();
 
         assert_eq!(
         "Bearer error=\"invalid_token\" error_description=\"Subject 8740827c-2e0a-447b-9716-d73042e4039d not found\"",
-        format!("{}", b)
+        format!("{bearer}")
     );
     }
 }