diff --git a/crates/shadowsocks-service/src/local/redir/sys/unix/bsd_pf.rs b/crates/shadowsocks-service/src/local/redir/sys/unix/bsd_pf.rs
index b7782079f620..c852c9d68499 100644
--- a/crates/shadowsocks-service/src/local/redir/sys/unix/bsd_pf.rs
+++ b/crates/shadowsocks-service/src/local/redir/sys/unix/bsd_pf.rs
@@ -281,7 +281,7 @@ impl PacketFilter {
 
             let states_count = states.ps_len as usize / mem::size_of::<pfsync_state>();
             for i in 0..states_count {
-                let state = &*(states.ps_u.psu_states.offset(i as isize));
+                let state = &*(states.ps_u.psu_states.add(i));
 
                 if state.proto == libc::IPPROTO_UDP as u8 {
                     cfg_if! {
diff --git a/crates/shadowsocks-service/src/local/redir/sys/unix/mod.rs b/crates/shadowsocks-service/src/local/redir/sys/unix/mod.rs
index 7a080386bca0..2c910bf870c6 100644
--- a/crates/shadowsocks-service/src/local/redir/sys/unix/mod.rs
+++ b/crates/shadowsocks-service/src/local/redir/sys/unix/mod.rs
@@ -13,12 +13,12 @@ cfg_if! {
                  target_os = "ios"))] {
         #[path = "pfvar_bindgen_macos.rs"]
         #[allow(dead_code, non_upper_case_globals, non_snake_case, non_camel_case_types)]
-        #[allow(clippy::useless_transmute)]
+        #[allow(clippy::useless_transmute, clippy::too_many_arguments, clippy::unnecessary_cast)]
         mod pfvar;
     } else if #[cfg(target_os = "freebsd")] {
         #[path = "pfvar_bindgen_freebsd.rs"]
         #[allow(dead_code, non_upper_case_globals, non_snake_case, non_camel_case_types)]
-        #[allow(clippy::useless_transmute)]
+        #[allow(clippy::useless_transmute, clippy::too_many_arguments, clippy::unnecessary_cast)]
         mod pfvar;
     }
 }
diff --git a/src/sys.rs b/src/sys.rs
index dc9501eba3a4..df9316d9868c 100644
--- a/src/sys.rs
+++ b/src/sys.rs
@@ -120,7 +120,7 @@ pub fn run_as_user(uname: &str) -> std::io::Result<()> {
             return Err(err);
         }
 
-        if libc::initgroups(pwd.pw_name, pwd.pw_gid.try_into().unwrap()) != 0 {
+        if libc::initgroups(pwd.pw_name, pwd.pw_gid as _) != 0 {
             let err = Error::last_os_error();
             error!(
                 "could not change supplementary groups to user {:?}'s gid: {}, uid: {}, error: {}",