diff --git a/doc/shadowsocks-libev.asciidoc b/doc/shadowsocks-libev.asciidoc
index 71b6bccd..5f69e452 100644
--- a/doc/shadowsocks-libev.asciidoc
+++ b/doc/shadowsocks-libev.asciidoc
@@ -64,7 +64,7 @@ aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
 camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
 chacha20-ietf-poly1305, salsa20, chacha20 and chacha20-ietf.
 +
-The default cipher is 'rc4-md5'.
+The default cipher is 'chacha20-ietf-poly1305'.
 +
 If built with PolarSSL or custom OpenSSL libraries, some of
 these ciphers may not work.
diff --git a/doc/ss-local.asciidoc b/doc/ss-local.asciidoc
index 931fcd54..0c7cbfde 100644
--- a/doc/ss-local.asciidoc
+++ b/doc/ss-local.asciidoc
@@ -59,7 +59,7 @@ aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
 camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
 chacha20-ietf-poly1305, salsa20, chacha20 and chacha20-ietf.
 +
-The default cipher is 'rc4-md5'.
+The default cipher is 'chacha20-ietf-poly1305'.
 +
 If built with PolarSSL or custom OpenSSL libraries, some of
 these ciphers may not work.
diff --git a/doc/ss-manager.asciidoc b/doc/ss-manager.asciidoc
index f344cffa..505c7d12 100644
--- a/doc/ss-manager.asciidoc
+++ b/doc/ss-manager.asciidoc
@@ -51,7 +51,7 @@ aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
 camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
 chacha20-ietf-poly1305, salsa20, chacha20 and chacha20-ietf.
 +
-The default cipher is 'rc4-md5'.
+The default cipher is 'chacha20-ietf-poly1305'.
 +
 If built with PolarSSL or custom OpenSSL libraries, some of
 these ciphers may not work.
diff --git a/doc/ss-redir.asciidoc b/doc/ss-redir.asciidoc
index 9355de1c..c03f0236 100644
--- a/doc/ss-redir.asciidoc
+++ b/doc/ss-redir.asciidoc
@@ -58,7 +58,7 @@ aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
 camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
 chacha20-ietf-poly1305, salsa20, chacha20 and chacha20-ietf.
 +
-The default cipher is 'rc4-md5'.
+The default cipher is 'chacha20-ietf-poly1305'.
 +
 If built with PolarSSL or custom OpenSSL libraries, some of
 these ciphers may not work.
diff --git a/doc/ss-tunnel.asciidoc b/doc/ss-tunnel.asciidoc
index b4b3e6ec..1e0e4fff 100644
--- a/doc/ss-tunnel.asciidoc
+++ b/doc/ss-tunnel.asciidoc
@@ -58,7 +58,7 @@ aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
 camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
 chacha20-ietf-poly1305, salsa20, chacha20 and chacha20-ietf.
 +
-The default cipher is 'rc4-md5'.
+The default cipher is 'chacha20-ietf-poly1305'.
 +
 If built with PolarSSL or custom OpenSSL libraries, some of
 these ciphers may not work.
diff --git a/src/aead.c b/src/aead.c
index 56cf30ad..9e2da725 100644
--- a/src/aead.c
+++ b/src/aead.c
@@ -719,8 +719,8 @@ aead_init(const char *pass, const char *key, const char *method)
                 break;
             }
         if (m >= AEAD_CIPHER_NUM) {
-            LOGE("Invalid cipher name: %s, use aes-256-gcm instead", method);
-            m = AES256GCM;
+            LOGE("Invalid cipher name: %s, use chacha20-ietf-poly1305 instead", method);
+            m = CHACHA20POLY1305IETF;
         }
     }
     return aead_key_init(m, pass, key);
diff --git a/src/local.c b/src/local.c
index 3cff2f75..94dcef39 100644
--- a/src/local.c
+++ b/src/local.c
@@ -1697,7 +1697,7 @@ main(int argc, char **argv)
     }
 
     if (method == NULL) {
-        method = "rc4-md5";
+        method = "chacha20-ietf-poly1305";
     }
 
     if (timeout == NULL) {
diff --git a/src/server.c b/src/server.c
index 4d7c70b0..30c03a41 100644
--- a/src/server.c
+++ b/src/server.c
@@ -1860,7 +1860,7 @@ main(int argc, char **argv)
     }
 
     if (method == NULL) {
-        method = "rc4-md5";
+        method = "chacha20-ietf-poly1305";
     }
 
     if (timeout == NULL) {
diff --git a/src/stream.c b/src/stream.c
index e6a798dc..3817dbbd 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -677,8 +677,8 @@ stream_init(const char *pass, const char *key, const char *method)
                 break;
             }
         if (m >= STREAM_CIPHER_NUM) {
-            LOGE("Invalid cipher name: %s, use rc4-md5 instead", method);
-            m = RC4_MD5;
+            LOGE("Invalid cipher name: %s, use chacha20-ietf instead", method);
+            m = CHACHA20IETF;
         }
     }
     if (m == TABLE) {
diff --git a/src/tunnel.c b/src/tunnel.c
index edd8a984..d6e12fb5 100644
--- a/src/tunnel.c
+++ b/src/tunnel.c
@@ -1021,7 +1021,7 @@ main(int argc, char **argv)
     }
 
     if (method == NULL) {
-        method = "rc4-md5";
+        method = "chacha20-ietf-poly1305";
     }
 
     if (timeout == NULL) {
diff --git a/src/utils.c b/src/utils.c
index 9461afd3..ca5763bc 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -317,7 +317,7 @@ usage()
     printf(
         "                                  salsa20, chacha20 and chacha20-ietf.\n");
     printf(
-        "                                  The default cipher is rc4-md5.\n");
+        "                                  The default cipher is chacha20-ietf-poly1305.\n");
     printf("\n");
     printf(
         "       [-a <user>]                Run as another user.\n");