diff --git a/Shadowsocks.Net/Crypto/CryptoFactory.cs b/Shadowsocks.Net/Crypto/CryptoFactory.cs
index 413e5d14..5eb7b492 100644
--- a/Shadowsocks.Net/Crypto/CryptoFactory.cs
+++ b/Shadowsocks.Net/Crypto/CryptoFactory.cs
@@ -42,12 +42,12 @@ namespace Shadowsocks.Net.Crypto
                     _registeredEncryptors.Add(method.Key, typeof(StreamAesCfbBouncyCastleCrypto));
                 }
             }
-            foreach (var method in StreamChachaNaClCrypto.SupportedCiphers())
+            foreach (var method in StreamChachaBouncyCastleCrypto.SupportedCiphers())
             {
                 if (!_registeredEncryptors.ContainsKey(method.Key))
                 {
                     ciphers.Add(method.Key, method.Value);
-                    _registeredEncryptors.Add(method.Key, typeof(StreamChachaNaClCrypto));
+                    _registeredEncryptors.Add(method.Key, typeof(StreamChachaBouncyCastleCrypto));
                 }
             }
 
diff --git a/Shadowsocks.Net/Crypto/Stream/StreamChachaBouncyCastleCrypto.cs b/Shadowsocks.Net/Crypto/Stream/StreamChachaBouncyCastleCrypto.cs
new file mode 100644
index 00000000..83a0e650
--- /dev/null
+++ b/Shadowsocks.Net/Crypto/Stream/StreamChachaBouncyCastleCrypto.cs
@@ -0,0 +1,59 @@
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.Engines;
+using Org.BouncyCastle.Crypto.Parameters;
+using System;
+using System.Collections.Generic;
+
+namespace Shadowsocks.Net.Crypto.Stream
+{
+    public class StreamChachaBouncyCastleCrypto : StreamCrypto
+    {
+        private readonly BufferedCipherBase _encryptor;
+
+        public StreamChachaBouncyCastleCrypto(string method, string password) : base(method, password)
+        {
+            _encryptor = new BufferedStreamCipher(new ChaCha7539Engine());
+        }
+
+        protected override void InitCipher(byte[] iv, bool isEncrypt)
+        {
+            base.InitCipher(iv, isEncrypt);
+            _encryptor.Init(isEncrypt, new ParametersWithIV(new KeyParameter(key), iv));
+        }
+
+        protected override int CipherEncrypt(ReadOnlySpan<byte> plain, Span<byte> cipher)
+        {
+            return CipherUpdate(plain, cipher);
+        }
+
+        protected override int CipherDecrypt(Span<byte> plain, ReadOnlySpan<byte> cipher)
+        {
+            return CipherUpdate(cipher, plain);
+        }
+
+        protected virtual int CipherUpdate(ReadOnlySpan<byte> input, Span<byte> output)
+        {
+            var i = input.ToArray();
+            var o = new byte[_encryptor.GetOutputSize(i.Length)];
+            var res = _encryptor.ProcessBytes(i, 0, i.Length, o, 0);
+            o.CopyTo(output);
+            return res;
+        }
+
+        #region Cipher Info
+        private static readonly Dictionary<string, CipherInfo> _ciphers = new Dictionary<string, CipherInfo>
+        {
+            { "chacha20-ietf", new CipherInfo("chacha20-ietf", 32, 12, CipherFamily.Chacha20) },
+        };
+        public static Dictionary<string, CipherInfo> SupportedCiphers()
+        {
+            return _ciphers;
+        }
+
+        protected override Dictionary<string, CipherInfo> GetCiphers()
+        {
+            return _ciphers;
+        }
+        #endregion
+    }
+}
diff --git a/Shadowsocks.Net/Crypto/Stream/StreamChachaNaClCrypto.cs b/Shadowsocks.Net/Crypto/Stream/StreamChachaNaClCrypto.cs
deleted file mode 100644
index df65762d..00000000
--- a/Shadowsocks.Net/Crypto/Stream/StreamChachaNaClCrypto.cs
+++ /dev/null
@@ -1,76 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Runtime.CompilerServices;
-using NaCl.Core;
-
-namespace Shadowsocks.Net.Crypto.Stream
-{
-    public class StreamChachaNaClCrypto : StreamCrypto
-    {
-        const int BlockSize = 64;
-
-        // tcp is stream, which can split into chunks at unexpected position...
-        // so we need some special handling, as we can't read all data before encrypt
-
-        // we did it in AEADEncryptor.cs for AEAD, it can operate at block level
-        // but we need do it ourselves in stream cipher.
-
-        // when new data arrive, put it on correct offset
-        // and update it, ignore other data, get it in correct offset...
-        readonly byte[] chachaBuf = new byte[MaxInputSize + BlockSize];
-        // the 'correct offset', always in 0~BlockSize range, so input data always fit into buffer
-        int remain = 0;
-        // increase counter manually...
-        int ic = 0;
-        public StreamChachaNaClCrypto(string method, string password) : base(method, password)
-        {
-        }
-
-        protected override int CipherDecrypt(Span<byte> plain, ReadOnlySpan<byte> cipher)
-        {
-            return CipherUpdate(cipher, plain, false);
-        }
-
-        protected override int CipherEncrypt(ReadOnlySpan<byte> plain, Span<byte> cipher)
-        {
-            return CipherUpdate(plain, cipher, true);
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private int CipherUpdate(ReadOnlySpan<byte> i, Span<byte> o, bool enc)
-        {
-            // about performance problem:
-            // as a part of hacking for streaming, we need manually increase IC
-            // so we need new Chacha20
-            // and to get correct position, copy paste array everytime is required
-            // NaCl.Core has no int Encrypt(ReadOnlySpan<byte>,Span<byte>)...
-
-            int len = i.Length;
-            int pad = remain;
-            i.CopyTo(chachaBuf.AsSpan(pad));
-            var chacha = new ChaCha20(key, ic);
-            var p = enc ? chacha.Encrypt(chachaBuf, iv) : chacha.Decrypt(chachaBuf, iv);
-            p.AsSpan(pad, len).CopyTo(o);
-            pad += len;
-            ic += pad / BlockSize;
-            remain = pad % BlockSize;
-            return len;
-        }
-
-        #region Cipher Info
-        private static readonly Dictionary<string, CipherInfo> _ciphers = new Dictionary<string, CipherInfo>
-        {
-            { "chacha20-ietf", new CipherInfo("chacha20-ietf", 32, 12, CipherFamily.Chacha20) },
-        };
-        public static Dictionary<string, CipherInfo> SupportedCiphers()
-        {
-            return _ciphers;
-        }
-
-        protected override Dictionary<string, CipherInfo> GetCiphers()
-        {
-            return _ciphers;
-        }
-        #endregion
-    }
-}
diff --git a/Shadowsocks.Net/Shadowsocks.Net.csproj b/Shadowsocks.Net/Shadowsocks.Net.csproj
index cc75b0b7..dbca59da 100644
--- a/Shadowsocks.Net/Shadowsocks.Net.csproj
+++ b/Shadowsocks.Net/Shadowsocks.Net.csproj
@@ -6,7 +6,6 @@
 
   <ItemGroup>
     <PackageReference Include="BouncyCastle.NetCore" Version="1.8.6" />
-    <PackageReference Include="NaCl.Core" Version="2.0.0" />
     <PackageReference Include="Splat" Version="9.6.1" />
   </ItemGroup>