diff --git a/hknweb/settings/common.py b/hknweb/settings/common.py
index 53c98c57..f9a40148 100644
--- a/hknweb/settings/common.py
+++ b/hknweb/settings/common.py
@@ -104,6 +104,7 @@
         "NAME": "hknweb",
         "HOST": "mysql",
         "OPTIONS": {
+            "charset": "utf8mb4",
             "init_command": "SET sql_mode='STRICT_TRANS_TABLES'",
             "read_default_file": "~/.my.cnf",
         },