@@ -273,7 +273,10 @@ def __init__(
                 ),
                 DeprecationWarning,
             )
-        if self.timestamp_field == self.created_timestamp_column:
+        if (
+            self.timestamp_field
+            and self.timestamp_field == self.created_timestamp_column
+        ):
             raise ValueError(
                 "Please do not use the same column for 'timestamp_field' and 'created_timestamp_column'."
             )
Original file line number	Diff line number	Diff line change
`@@ -273,7 +273,10 @@ def __init__(`
`273`	`273`	`),`
`274`	`274`	`DeprecationWarning,`
`275`	`275`	`)`
`276`		`- if self.timestamp_field == self.created_timestamp_column:`
	`276`	`+ if (`
	`277`	`+ self.timestamp_field`
	`278`	`+ and self.timestamp_field == self.created_timestamp_column`
	`279`	`+ ):`
`277`	`280`	`raise ValueError(`
`278`	`281`	`"Please do not use the same column for 'timestamp_field' and 'created_timestamp_column'."`
`279`	`282`	`)`