diff --git a/pytato/array.py b/pytato/array.py
index 31fe0b126..21eec352d 100644
--- a/pytato/array.py
+++ b/pytato/array.py
@@ -449,9 +449,9 @@ class Array(Taggable):
     tags: FrozenSet[Tag] = attrs.field(kw_only=True)
 
     # These are automatically excluded from equality in EqualityComparer
-    non_equality_tags: FrozenSet[Optional[Tag]] = attrs.field(kw_only=True,
-                                                              hash=False,
-                                                              default=frozenset())
+    non_equality_tags: FrozenSet[Tag] = attrs.field(kw_only=True,
+                                                    hash=False,
+                                                    default=frozenset())
 
     _mapper_method: ClassVar[str]
 
diff --git a/pytato/distributed/nodes.py b/pytato/distributed/nodes.py
index ac7cc5ac2..ec2d17417 100644
--- a/pytato/distributed/nodes.py
+++ b/pytato/distributed/nodes.py
@@ -148,7 +148,7 @@ class DistributedSendRefHolder(Array):
 
     def __init__(self, send: DistributedSend, passthrough_data: Array,
                  tags: FrozenSet[Tag] = frozenset(),
-                 non_equality_tags: FrozenSet[Optional[Tag]] = frozenset()) -> None:
+                 non_equality_tags: FrozenSet[Tag] = frozenset()) -> None:
         super().__init__(axes=passthrough_data.axes, tags=tags,
                          non_equality_tags=non_equality_tags)
         object.__setattr__(self, "send", send)
@@ -232,7 +232,7 @@ def make_distributed_send_ref_holder(
         send: DistributedSend,
         passthrough_data: Array,
         tags: FrozenSet[Tag] = frozenset(),
-        non_equality_tags: FrozenSet[Optional[Tag]] = frozenset(),
+        non_equality_tags: FrozenSet[Tag] = frozenset(),
         ) -> DistributedSendRefHolder:
     """Make a :class:`DistributedSendRefHolder` object."""
     if not non_equality_tags:
diff --git a/pytato/utils.py b/pytato/utils.py
index e5463d8f5..2097514d3 100644
--- a/pytato/utils.py
+++ b/pytato/utils.py
@@ -180,7 +180,7 @@ def broadcast_binary_op(a1: ArrayOrScalar, a2: ArrayOrScalar,
                         op: Callable[[ScalarExpression, ScalarExpression], ScalarExpression],  # noqa:E501
                         get_result_type: Callable[[DtypeOrScalar, DtypeOrScalar], np.dtype[Any]],  # noqa:E501
                         tags: FrozenSet[Tag],
-                        non_equality_tags: FrozenSet[Optional[Tag]],
+                        non_equality_tags: FrozenSet[Tag],
                         ) -> ArrayOrScalar:
     from pytato.array import _get_default_axes
 
@@ -481,7 +481,7 @@ def _index_into(
         ary: Array,
         indices: Tuple[ConvertibleToIndexExpr, ...],
         tags: FrozenSet[Tag],
-        non_equality_tags: FrozenSet[Optional[Tag]]) -> Array:
+        non_equality_tags: FrozenSet[Tag]) -> Array:
     from pytato.diagnostic import CannotBroadcastError
     from pytato.array import _get_default_axes