diff --git a/enc/euc_cn.c b/enc/euc_cn.c
index b6494f91ac..c30f4aa847 100644
--- a/enc/euc_cn.c
+++ b/enc/euc_cn.c
@@ -9,3 +9,4 @@ Init_euc_cn(void)
 }
 
 ENC_ALIAS("eucCN", "EUC-CN");
+ENC_ALIAS("GB2312", "EUC-CN");
diff --git a/enc/gb18030.c b/enc/gb18030.c
index 1d48ef23d6..65666ec3af 100644
--- a/enc/gb18030.c
+++ b/enc/gb18030.c
@@ -493,6 +493,4 @@ OnigEncodingDefine(gb18030, GB18030) = {
   gb18030_left_adjust_char_head,
   gb18030_is_allowed_reverse_match
 };
-ENC_REPLICATE("GBK", "GB18030");
-ENC_REPLICATE("CP936", "GB18030");
-ENC_ALIAS("Windows-936", "GBK");
+