diff --git a/gcloud/datastore/query.py b/gcloud/datastore/query.py
index 28461b69b165..b28bbf0ba0ce 100644
--- a/gcloud/datastore/query.py
+++ b/gcloud/datastore/query.py
@@ -90,7 +90,10 @@ def __init__(self,
         self._kind = kind
         self._namespace = namespace
         self._ancestor = ancestor
-        self._filters = list(filters)
+        self._filters = []
+        # Verify filters passed in.
+        for property_name, operator, value in filters:
+            self.add_filter(property_name, operator, value)
         self._projection = _ensure_tuple_or_list('projection', projection)
         self._order = _ensure_tuple_or_list('order', order)
         self._group_by = _ensure_tuple_or_list('group_by', group_by)
@@ -216,11 +219,8 @@ def add_filter(self, property_name, operator, value):
             choices_message = 'Please use one of: =, <, <=, >, >=.'
             raise ValueError(error_message, choices_message)
 
-        if property_name == '__key__':
-            if not isinstance(value, Key):
-                raise ValueError('Invalid key: "%s"' % value)
-            if operator != '=':
-                raise ValueError('Invalid operator for key: "%s"' % operator)
+        if property_name == '__key__' and not isinstance(value, Key):
+            raise ValueError('Invalid key: "%s"' % value)
 
         self._filters.append((property_name, operator, value))
 
diff --git a/gcloud/datastore/test_query.py b/gcloud/datastore/test_query.py
index 3ffee7f5d75d..b3488d556a75 100644
--- a/gcloud/datastore/test_query.py
+++ b/gcloud/datastore/test_query.py
@@ -100,6 +100,13 @@ def test_ctor_bad_group_by(self):
         self.assertRaises(TypeError, self._makeOne, _KIND, _DATASET,
                           group_by=BAD_GROUP_BY)
 
+    def test_ctor_bad_filters(self):
+        _DATASET = 'DATASET'
+        _KIND = 'KIND'
+        FILTERS_CANT_UNPACK = [('one', 'two')]
+        self.assertRaises(ValueError, self._makeOne, _KIND, _DATASET,
+                          filters=FILTERS_CANT_UNPACK)
+
     def test_namespace_setter_w_non_string(self):
         _DATASET = 'DATASET'
         query = self._makeOne(dataset_id=_DATASET)
@@ -224,12 +231,13 @@ def test_add_filter___key__valid_key(self):
         query.add_filter('__key__', '=', key)
         self.assertEqual(query.filters, [('__key__', '=', key)])
 
-    def test_filter___key__invalid_operator(self):
+    def test_filter___key__not_equal_operator(self):
         from gcloud.datastore.key import Key
         _DATASET = 'DATASET'
         key = Key('Foo', dataset_id='DATASET')
         query = self._makeOne(dataset_id=_DATASET)
-        self.assertRaises(ValueError, query.add_filter, '__key__', '<', key)
+        query.add_filter('__key__', '<', key)
+        self.assertEqual(query.filters, [('__key__', '<', key)])
 
     def test_filter___key__invalid_value(self):
         _DATASET = 'DATASET'