diff --git a/crates/shadowsocks-service/src/config.rs b/crates/shadowsocks-service/src/config.rs
index 6c7c892f..9c80ab4d 100644
--- a/crates/shadowsocks-service/src/config.rs
+++ b/crates/shadowsocks-service/src/config.rs
@@ -305,7 +305,7 @@ cfg_if! {
                     /// Available TCP transparent proxy types
                     #[doc(hidden)]
                     pub fn tcp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[RedirType::Redirect.name(), RedirType::TProxy.name()];
+                        const AVAILABLE_TYPES: &[&str] = &[RedirType::Redirect.name(), RedirType::TProxy.name()];
                         AVAILABLE_TYPES
                     }
 
@@ -317,7 +317,7 @@ cfg_if! {
                     /// Available UDP transparent proxy types
                     #[doc(hidden)]
                     pub fn udp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[RedirType::TProxy.name()];
+                        const AVAILABLE_TYPES: &[&str] = &[RedirType::TProxy.name()];
                         AVAILABLE_TYPES
                     }
                 } else if #[cfg(any(target_os = "openbsd", target_os = "freebsd"))] {
@@ -329,7 +329,7 @@ cfg_if! {
                     /// Available TCP transparent proxy types
                     #[doc(hidden)]
                     pub fn tcp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
+                        const AVAILABLE_TYPES: &[&str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
                         AVAILABLE_TYPES
                     }
 
@@ -341,7 +341,7 @@ cfg_if! {
                     /// Available UDP transparent proxy types
                     #[doc(hidden)]
                     pub const fn udp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
+                        const AVAILABLE_TYPES: &[&str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
                         AVAILABLE_TYPES
                     }
                 } else if #[cfg(any(target_os = "netbsd", target_os = "solaris", target_os = "macos", target_os = "ios"))] {
@@ -353,7 +353,7 @@ cfg_if! {
                     /// Available TCP transparent proxy types
                     #[doc(hidden)]
                     pub const fn tcp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
+                        const AVAILABLE_TYPES: &[&str] = &[RedirType::PacketFilter.name(), RedirType::IpFirewall.name()];
                         AVAILABLE_TYPES
                     }
 
@@ -365,7 +365,7 @@ cfg_if! {
                     /// Available UDP transparent proxy types
                     #[doc(hidden)]
                     pub const fn udp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[];
+                        const AVAILABLE_TYPES: &[&str] = &[];
                         AVAILABLE_TYPES
                     }
                 } else {
@@ -377,7 +377,7 @@ cfg_if! {
                     /// Available TCP transparent proxy types
                     #[doc(hidden)]
                     pub const fn tcp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[];
+                        const AVAILABLE_TYPES: &[&str] = &[];
                         AVAILABLE_TYPES
                     }
 
@@ -389,7 +389,7 @@ cfg_if! {
                     /// Available UDP transparent proxy types
                     #[doc(hidden)]
                     pub const fn udp_available_types() -> &'static [&'static str] {
-                        const AVAILABLE_TYPES: &'static [&'static str] = &[];
+                        const AVAILABLE_TYPES: &[&str] = &[];
                         AVAILABLE_TYPES
                     }
                 }
diff --git a/crates/shadowsocks-service/src/local/socks/server/mod.rs b/crates/shadowsocks-service/src/local/socks/server/mod.rs
index 9969a7d2..894cee30 100644
--- a/crates/shadowsocks-service/src/local/socks/server/mod.rs
+++ b/crates/shadowsocks-service/src/local/socks/server/mod.rs
@@ -187,7 +187,7 @@ impl Socks {
             version => {
                 error!("unsupported socks version {:x}", version);
                 let err = io::Error::new(ErrorKind::Other, "unsupported socks version");
-                return Err(err);
+                Err(err)
             }
         }
     }
diff --git a/crates/shadowsocks/src/relay/udprelay/crypto_io.rs b/crates/shadowsocks/src/relay/udprelay/crypto_io.rs
index a2543ee8..279a6b8b 100644
--- a/crates/shadowsocks/src/relay/udprelay/crypto_io.rs
+++ b/crates/shadowsocks/src/relay/udprelay/crypto_io.rs
@@ -189,7 +189,7 @@ async fn decrypt_payload_stream(
     trace!("UDP packet got stream IV {:?}", ByteStr::new(iv));
     let mut cipher = Cipher::new(method, key, iv);
 
-    assert_eq!(cipher.decrypt_packet(data), true);
+    assert!(cipher.decrypt_packet(data));
 
     let (dn, addr) = parse_packet(data).await?;