diff --git a/src/textual/dom.py b/src/textual/dom.py
index e68939b39..56b9e8770 100644
--- a/src/textual/dom.py
+++ b/src/textual/dom.py
@@ -1,12 +1,12 @@
 from __future__ import annotations
 
 import re
+from functools import lru_cache
 from inspect import getfile
 from typing import (
     TYPE_CHECKING,
     ClassVar,
     Iterable,
-    Iterator,
     Sequence,
     Type,
     TypeVar,
@@ -224,13 +224,14 @@ class DOMNode(MessagePump):
         Reactive._initialize_object(self)
 
     @property
-    def _node_bases(self) -> Iterator[Type[DOMNode]]:
+    def _node_bases(self) -> Sequence[Type[DOMNode]]:
         """The DOMNode bases classes (including self.__class__)"""
         # Node bases are in reversed order so that the base class is lower priority
         return self._css_bases(self.__class__)
 
     @classmethod
-    def _css_bases(cls, base: Type[DOMNode]) -> Iterator[Type[DOMNode]]:
+    @lru_cache(maxsize=None)
+    def _css_bases(cls, base: Type[DOMNode]) -> Sequence[Type[DOMNode]]:
         """Get the DOMNode base classes, which inherit CSS.
 
         Args:
@@ -239,9 +240,10 @@ class DOMNode(MessagePump):
         Returns:
             An iterable of DOMNode classes.
         """
+        classes: list[type[DOMNode]] = []
         _class = base
         while True:
-            yield _class
+            classes.append(_class)
             if not _class._inherit_css:
                 break
             for _base in _class.__bases__:
@@ -250,6 +252,7 @@ class DOMNode(MessagePump):
                     break
             else:
                 break
+        return classes
 
     @classmethod
     def _merge_bindings(cls) -> Bindings:
@@ -314,7 +317,9 @@ class DOMNode(MessagePump):
 
         return css_stack
 
-    def _get_component_classes(self) -> set[str]:
+    @classmethod
+    @lru_cache(maxsize=None)
+    def _get_component_classes(cls) -> frozenset[str]:
         """Gets the component classes for this class and inherited from bases.
 
         Component classes are inherited from base classes, unless
@@ -325,12 +330,12 @@ class DOMNode(MessagePump):
         """
 
         component_classes: set[str] = set()
-        for base in self._node_bases:
+        for base in cls._css_bases(cls):
             component_classes.update(base.__dict__.get("COMPONENT_CLASSES", set()))
             if not base.__dict__.get("_inherit_component_classes", True):
                 break
 
-        return component_classes
+        return frozenset(component_classes)
 
     @property
     def parent(self) -> DOMNode | None:
diff --git a/tests/test_dom.py b/tests/test_dom.py
index f366d0706..b78a958c9 100644
--- a/tests/test_dom.py
+++ b/tests/test_dom.py
@@ -157,7 +157,7 @@ def test_component_classes_inheritance():
     f = F()
     f_cc = f._get_component_classes()
 
-    assert node_cc == set()
+    assert node_cc == frozenset()
     assert a_cc == {"a-1", "a-2"}
     assert b_cc == {"b-1"}
     assert c_cc == {"b-1", "c-1", "c-2"}