diff --git a/README.md b/README.md
index 77fd29ec..564dbb75 100644
--- a/README.md
+++ b/README.md
@@ -273,7 +273,7 @@ Mysql2::Client.new(
   :database,
   :socket = '/path/to/mysql.sock',
   :flags = REMEMBER_OPTIONS | LONG_PASSWORD | LONG_FLAG | TRANSACTIONS | PROTOCOL_41 | SECURE_CONNECTION | MULTI_STATEMENTS,
-  :encoding = 'utf8',
+  :encoding = 'utf8mb4',
   :read_timeout = seconds,
   :write_timeout = seconds,
   :connect_timeout = seconds,
@@ -367,7 +367,7 @@ Use the value `mysql2` as the adapter name. For example:
 ``` yaml
 development:
   adapter: mysql2
-  encoding: utf8
+  encoding: utf8mb4
   database: my_db_name
   username: root
   password: my_password
diff --git a/lib/mysql2/client.rb b/lib/mysql2/client.rb
index 9811835e..2bb81a87 100644
--- a/lib/mysql2/client.rb
+++ b/lib/mysql2/client.rb
@@ -45,8 +45,8 @@ def initialize(opts = {})
         end
       end
 
-      # force the encoding to utf8
-      self.charset_name = opts[:encoding] || 'utf8'
+      # force the encoding to utf8mb4
+      self.charset_name = opts[:encoding] || 'utf8mb4'
 
       mode = parse_ssl_mode(opts[:ssl_mode]) if opts[:ssl_mode]
       if (mode == SSL_MODE_VERIFY_CA || mode == SSL_MODE_VERIFY_IDENTITY) && !opts[:sslca]