diff --git a/pymysql/cursors.py b/pymysql/cursors.py
index 2b5ccca9..b36f473c 100644
--- a/pymysql/cursors.py
+++ b/pymysql/cursors.py
@@ -95,13 +95,6 @@ def _nextset(self, unbuffered=False):
     def nextset(self):
         return self._nextset(False)
 
-    def _ensure_bytes(self, x, encoding=None):
-        if isinstance(x, str):
-            x = x.encode(encoding)
-        elif isinstance(x, (tuple, list)):
-            x = type(x)(self._ensure_bytes(v, encoding=encoding) for v in x)
-        return x
-
     def _escape_args(self, args, conn):
         if isinstance(args, (tuple, list)):
             return tuple(conn.literal(arg) for arg in args)