diff --git a/grafanalib/core.py b/grafanalib/core.py
index 6f368642..cb33222b 100644
--- a/grafanalib/core.py
+++ b/grafanalib/core.py
@@ -3223,7 +3223,10 @@ class Table(Panel):
     showHeader = attr.ib(default=True, validator=instance_of(bool))
     span = attr.ib(default=6),
     unit = attr.ib(default='', validator=instance_of(str))
-    sortBy = attr.ib(default=attr.Factory(list))
+    sortBy = attr.ib(default=attr.Factory(list), validator=attr.validators.deep_iterable(
+        member_validator=instance_of(TableSortByField),
+        iterable_validator=instance_of(list)
+    ))
 
     @classmethod
     def with_styled_columns(cls, columns, styles=None, **kwargs):