diff --git a/Cargo.toml b/Cargo.toml
index 72507e9..0dc9b71 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 authors = ["Y. T. Chung <zonyitoo@gmail.com>"]
 name = "mqtt-protocol"
-version = "0.10.0"
+version = "0.11.0"
 license = "MIT/Apache-2.0"
 description = "MQTT Protocol Library"
 keywords = ["mqtt", "protocol"]
@@ -21,8 +21,7 @@ thiserror = "1.0"
 
 [dev-dependencies]
 clap = "2"
-env_logger = "0.7"
-time = "0.1"
+env_logger = "0.8"
 tokio = { version = "1.0", features = ["macros", "rt-multi-thread", "net", "time", "io-util"] }
 futures = { version = "0.3" }
 uuid = { version = "0.8", features = ["v4"] }
diff --git a/README.md b/README.md
index a742b39..78ae7c1 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ MQTT protocol library for Rust
 
 ```toml
 [dependencies]
-mqtt-protocol = "0.8"
+mqtt-protocol = "0.11"
 ```
 
 ## Usage
diff --git a/examples/sub-client.rs b/examples/sub-client.rs
index eeb9937..5aceaae 100644
--- a/examples/sub-client.rs
+++ b/examples/sub-client.rs
@@ -3,13 +3,14 @@ extern crate mqtt;
 extern crate log;
 extern crate clap;
 extern crate env_logger;
-extern crate time;
 extern crate uuid;
 
 use std::env;
 use std::io::Write;
 use std::net::TcpStream;
 use std::str;
+use std::thread;
+use std::time::{Duration, Instant};
 
 use clap::{App, Arg};
 
@@ -20,9 +21,6 @@ use mqtt::packet::*;
 use mqtt::TopicFilter;
 use mqtt::{Decodable, Encodable, QualityOfService};
 
-use std::thread;
-use std::time::Duration;
-
 fn generate_client_id() -> String {
     format!("/MQTT/rust/{}", Uuid::new_v4())
 }
@@ -138,10 +136,10 @@ fn main() {
 
     let mut stream_clone = stream.try_clone().unwrap();
     thread::spawn(move || {
-        let mut last_ping_time = 0;
-        let mut next_ping_time = last_ping_time + (keep_alive as f32 * 0.9) as i64;
+        let mut last_ping_time = Instant::now();
+        let mut next_ping_time = last_ping_time + Duration::from_secs((keep_alive as f32 * 0.9) as u64);
         loop {
-            let current_timestamp = time::get_time().sec;
+            let current_timestamp = Instant::now();
             if keep_alive > 0 && current_timestamp >= next_ping_time {
                 info!("Sending PINGREQ to broker");
 
@@ -152,7 +150,7 @@ fn main() {
                 stream_clone.write_all(&buf[..]).unwrap();
 
                 last_ping_time = current_timestamp;
-                next_ping_time = last_ping_time + (keep_alive as f32 * 0.9) as i64;
+                next_ping_time = last_ping_time + Duration::from_secs((keep_alive as f32 * 0.9) as u64);
                 thread::sleep(Duration::new((keep_alive / 2) as u64, 0));
             }
         }