diff --git a/shadowsocks/crypto/openssl.py b/shadowsocks/crypto/openssl.py
index 7bce8b3..6d4d154 100644
--- a/shadowsocks/crypto/openssl.py
+++ b/shadowsocks/crypto/openssl.py
@@ -322,9 +322,9 @@ def run_method(method):
 def run_aead_method(method, key_len=16):
 
     print(method, ': [payload][tag]', key_len)
-    cipher = libcrypto.EVP_get_cipherbyname(method)
+    cipher = libcrypto.EVP_get_cipherbyname(common.to_bytes(method))
     if not cipher:
-        cipher = load_cipher(method)
+        cipher = load_cipher(common.to_bytes(method))
     if not cipher:
         print('cipher not avaiable, please upgrade openssl')
         return
@@ -338,9 +338,9 @@ def run_aead_method(method, key_len=16):
 def run_aead_method_chunk(method, key_len=16):
 
     print(method, ': chunk([size][tag][payload][tag]', key_len)
-    cipher = libcrypto.EVP_get_cipherbyname(method)
+    cipher = libcrypto.EVP_get_cipherbyname(common.to_bytes(method))
     if not cipher:
-        cipher = load_cipher(method)
+        cipher = load_cipher(common.to_bytes(method))
     if not cipher:
         print('cipher not avaiable, please upgrade openssl')
         return