diff --git a/Cargo.lock b/Cargo.lock
index fce103533f9a..2311f23112da 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 [root]
 name = "shadowsocks-rust"
-version = "1.6.2"
+version = "1.6.3"
 dependencies = [
  "base64 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byte_string 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -12,7 +12,7 @@ dependencies = [
  "futures 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.30 (registry+https://github.com/rust-lang/crates.io-index)",
- "libsodium-ffi 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libsodium-ffi 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru_time_cache 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "md-5 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -273,7 +273,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "libsodium-ffi"
-version = "0.1.5"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.30 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -785,7 +785,7 @@ dependencies = [
 "checksum lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "3b37545ab726dd833ec6420aaba8231c5b320814b9029ad585555d2a03e94fbf"
 "checksum lazycell 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3b585b7a6811fb03aa10e74b278a0f00f8dd9b45dc681f148bb29fa5cb61859b"
 "checksum libc 0.2.30 (registry+https://github.com/rust-lang/crates.io-index)" = "2370ca07ec338939e356443dac2296f581453c35fe1e3a3ed06023c49435f915"
-"checksum libsodium-ffi 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "5fb58d1e29baea19145d12f3b17d2caf3e4da0ae2f181abb138e94fb226e43b6"
+"checksum libsodium-ffi 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "135fe5453bbdf2e3b8dfe102a0277538b2cfed9261d921a098a67bddfe393e13"
 "checksum log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "880f77541efa6e5cc74e76910c9884d9859683118839d6a1dc3b11e63512565b"
 "checksum lru_time_cache 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4bf17862cdf1a87c7cc0cccc498552f3e564d2ae61069f83d2279a932af4a00c"
 "checksum magenta 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4bf0336886480e671965f794bc9b6fce88503563013d1bfb7a502c81fe3ac527"
diff --git a/Cargo.toml b/Cargo.toml
index 930d08781ee0..f29374b247d9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "shadowsocks-rust"
-version = "1.6.2"
+version = "1.6.3"
 authors = ["Y. T. CHUNG <zonyitoo@gmail.com>"]
 description = "shadowsocks is a fast tunnel proxy that helps you bypass firewalls."
 repository = "https://github.com/zonyitoo/shadowsocks-rust"
diff --git a/README.md b/README.md
index 5d0da657b394..8b097fd8294d 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ shadowsocks is a fast tunnel proxy that helps you <del>bypass firewalls</del>.
 ## Dependencies
 
 * libcrypto (OpenSSL)
-* libsodium (Required for ciphers that are provided by libsodium)
+* libsodium >= 1.0.7 (Required for ciphers that are provided by libsodium)
 
 ## Usage
 
diff --git a/src/crypto/aead.rs b/src/crypto/aead.rs
index 9e7a3892e65d..67ffd4ad2d40 100644
--- a/src/crypto/aead.rs
+++ b/src/crypto/aead.rs
@@ -10,6 +10,8 @@ use ring::hmac::SigningKey;
 
 use bytes::{Bytes, BytesMut};
 
+use libsodium_ffi::sodium_increment;
+
 /// Encryptor API for AEAD ciphers
 pub trait AeadEncryptor {
     /// Encrypt `input` to `output` with `tag`. `output.len()` should equals to `input.len()`.
@@ -102,14 +104,7 @@ pub fn make_skey(t: CipherType, key: &[u8], salt: &[u8]) -> Bytes {
 ///
 /// AEAD ciphers requires to increase nonce after encrypt/decrypt every chunk
 pub fn increase_nonce(nonce: &mut [u8]) {
-    let mut adding = true;
-    for v in nonce.iter_mut() {
-        if !adding {
-            break;
-        }
-
-        let (r, overflow) = v.overflowing_add(1);
-        *v = r;
-        adding = overflow;
+    unsafe {
+        sodium_increment(nonce.as_mut_ptr(), nonce.len());
     }
 }