diff --git a/benches/benches.rs b/benches/benches.rs
index 6b034e269..63ca57fa2 100644
--- a/benches/benches.rs
+++ b/benches/benches.rs
@@ -12,7 +12,6 @@ mod suites;
 pub const DEFAULT_RAFT_SETS: [(usize, usize); 4] = [(0, 0), (3, 1), (5, 2), (7, 3)];
 
 fn main() {
-    criterion::init_logging();
     let mut c = Criterion::default()
         // Configure defaults before overriding with args.
         .warm_up_time(Duration::from_millis(500))
diff --git a/src/lib.rs b/src/lib.rs
index 412fca4cd..29707f0ec 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -261,7 +261,6 @@ For more information, check out an [example](examples/single_mem_node/main.rs#L1
 */
 
 #![cfg_attr(not(feature = "cargo-clippy"), allow(unknown_lints))]
-#![cfg_attr(feature = "cargo-clippy", feature(tool_lints))]
 #![deny(missing_docs)]
 
 #[cfg(feature = "failpoint")]
diff --git a/src/raft.rs b/src/raft.rs
index abc8fb2c5..713f9a497 100644
--- a/src/raft.rs
+++ b/src/raft.rs
@@ -679,7 +679,7 @@ impl<T: Storage> Raft<T> {
 
         self.election_elapsed = 0;
         let m = new_message(INVALID_ID, MessageType::MsgHup, Some(self.id));
-        self.step(m).is_ok();
+        let _ = self.step(m);
         true
     }
 
@@ -695,7 +695,7 @@ impl<T: Storage> Raft<T> {
             if self.check_quorum {
                 let m = new_message(INVALID_ID, MessageType::MsgCheckQuorum, Some(self.id));
                 has_ready = true;
-                self.step(m).is_ok();
+                let _ = self.step(m);
             }
             if self.state == StateRole::Leader && self.lead_transferee.is_some() {
                 self.abort_leader_transfer()
@@ -710,7 +710,7 @@ impl<T: Storage> Raft<T> {
             self.heartbeat_elapsed = 0;
             has_ready = true;
             let m = new_message(INVALID_ID, MessageType::MsgBeat, Some(self.id));
-            self.step(m).is_ok();
+            let _ = self.step(m);
         }
         has_ready
     }
@@ -794,7 +794,7 @@ impl<T: Storage> Raft<T> {
     }
 
     fn num_pending_conf(&self, ents: &[Entry]) -> usize {
-        ents.into_iter()
+        ents.iter()
             .filter(|e| e.get_entry_type() == EntryType::EntryConfChange)
             .count()
     }
diff --git a/src/raw_node.rs b/src/raw_node.rs
index 94da81d85..350812b11 100644
--- a/src/raw_node.rs
+++ b/src/raw_node.rs
@@ -443,7 +443,7 @@ impl<T: Storage> RawNode<T> {
         m.set_msg_type(MessageType::MsgUnreachable);
         m.set_from(id);
         // we don't care if it is ok actually
-        self.raft.step(m).is_ok();
+        let _ = self.raft.step(m);
     }
 
     /// ReportSnapshot reports the status of the sent snapshot.
@@ -454,7 +454,7 @@ impl<T: Storage> RawNode<T> {
         m.set_from(id);
         m.set_reject(rej);
         // we don't care if it is ok actually
-        self.raft.step(m).is_ok();
+        let _ = self.raft.step(m);
     }
 
     /// TransferLeader tries to transfer leadership to the given transferee.
@@ -462,7 +462,7 @@ impl<T: Storage> RawNode<T> {
         let mut m = Message::new();
         m.set_msg_type(MessageType::MsgTransferLeader);
         m.set_from(transferee);
-        self.raft.step(m).is_ok();
+        let _ = self.raft.step(m);
     }
 
     /// ReadIndex requests a read state. The read state will be set in ready.
@@ -475,7 +475,7 @@ impl<T: Storage> RawNode<T> {
         let mut e = Entry::new();
         e.set_data(rctx);
         m.set_entries(RepeatedField::from_vec(vec![e]));
-        self.raft.step(m).is_ok();
+        let _ = self.raft.step(m);
     }
 
     /// Returns the store as an immutable reference.