diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py
index 9583a9859bfd..e1d6ea34daac 100644
--- a/python/pyspark/sql/functions.py
+++ b/python/pyspark/sql/functions.py
@@ -25,6 +25,9 @@
 if sys.version < "3":
     from itertools import imap as map
 
+if sys.version >= '3':
+    basestring = str
+
 from pyspark import since, SparkContext
 from pyspark.rdd import ignore_unicode_prefix, PythonEvalType
 from pyspark.sql.column import Column, _to_java_column, _to_seq, _create_column_from_literal