diff --git a/python/pyspark/mllib/linalg.py b/python/pyspark/mllib/linalg.py
index 597012b1c967c..f5aad28afda0f 100644
--- a/python/pyspark/mllib/linalg.py
+++ b/python/pyspark/mllib/linalg.py
@@ -152,6 +152,9 @@ def deserialize(self, datum):
         else:
             raise ValueError("do not recognize type %r" % tpe)
 
+    def simpleString(self):
+        return "vector"
+
 
 class Vector(object):
 
diff --git a/python/pyspark/sql/types.py b/python/pyspark/sql/types.py
index 31a861e1feb46..0169028ccc4eb 100644
--- a/python/pyspark/sql/types.py
+++ b/python/pyspark/sql/types.py
@@ -468,7 +468,7 @@ def deserialize(self, datum):
         raise NotImplementedError("UDT must implement deserialize().")
 
     def simpleString(self):
-        return 'null'
+        return 'udt'
 
     def json(self):
         return json.dumps(self.jsonValue(), separators=(',', ':'), sort_keys=True)