diff --git a/Cargo.toml b/Cargo.toml
index 5a877b1..db8158e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,6 +18,7 @@ integration-tests = []
 name = "tikv_client"
 
 [dependencies]
+regex = "1"
 failure = "0.1"
 futures-preview = { version = "0.3.0-alpha.15", features = ["compat"] }
 grpcio = { version = "0.5.0-alpha", features = [ "secure", "prost-codec" ], default-features = false }
diff --git a/src/errors.rs b/src/errors.rs
index 716a4f3..65d12e1 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -95,7 +95,7 @@ pub enum ErrorKind {
 }
 
 impl Fail for Error {
-    fn cause(&self) -> Option<&Fail> {
+    fn cause(&self) -> Option<&dyn Fail> {
         self.inner.cause()
     }
 
diff --git a/src/rpc/security.rs b/src/rpc/security.rs
index ee8f338..20d97be 100644
--- a/src/rpc/security.rs
+++ b/src/rpc/security.rs
@@ -9,10 +9,16 @@ use std::{
 };
 
 use grpcio::{Channel, ChannelBuilder, ChannelCredentialsBuilder, Environment};
+use lazy_static::*;
 use log::*;
+use regex::Regex;
 
 use crate::Result;
 
+lazy_static! {
+    static ref SCHEME_REG: Regex = Regex::new(r"^\s*(https?://)").unwrap();
+}
+
 fn check_pem_file(tag: &str, path: &Path) -> Result<File> {
     File::open(path)
         .map_err(|e| internal_err!("failed to open {} to load {}: {:?}", path.display(), tag, e))
@@ -65,21 +71,21 @@ impl SecurityManager {
         Factory: FnOnce(Channel) -> Client,
     {
         info!("connect to rpc server at endpoint: {:?}", addr);
-        let addr = addr
-            .trim_start_matches("http://")
-            .trim_start_matches("https://");
+
+        let addr = SCHEME_REG.replace(addr, "");
+
         let cb = ChannelBuilder::new(env)
             .keepalive_time(Duration::from_secs(10))
             .keepalive_timeout(Duration::from_secs(3));
 
         let channel = if self.ca.is_empty() {
-            cb.connect(addr)
+            cb.connect(&addr)
         } else {
             let cred = ChannelCredentialsBuilder::new()
                 .root_cert(self.ca.clone())
                 .cert(self.cert.clone(), load_pem_file("private key", &self.key)?)
                 .build();
-            cb.secure_connect(addr, cred)
+            cb.secure_connect(&addr, cred)
         };
 
         Ok(factory(channel))