diff --git a/doc/conf.py b/doc/conf.py
index 2991a2f4b73a6fbb8708a57fce8ce6a4d9cd84a0..74912f3b60cec2847995acf374b8c076c42becd4 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -35,5 +35,5 @@ sys.PYTATO_BUILDING_SPHINX_DOCS = True
 nitpick_ignore_regex = [
     ["py:class", r"numpy.(u?)int[\d]+"],
     ["py:class", r"pyrsistent.typing.(.+)"],
-
+    ["py:class", r"typing_extensions(.+)"],
 ]
diff --git a/pytato/transform.py b/pytato/transform.py
index d16c865091d5591b743b5a9934b623e091765a7a..04a19f7ee86793aa7a2ca1c905adf7c754176744 100644
--- a/pytato/transform.py
+++ b/pytato/transform.py
@@ -1716,10 +1716,11 @@ def _get_data_dedup_cache_key(ary: DataInterface) -> Hashable:
     import sys
     if "pyopencl" in sys.modules:
         from pyopencl.array import Array as CLArray  # type: ignore[import]
-        from pyopencl import Buffer as CLBuffer
+        from pyopencl import MemoryObjectHolder
         if isinstance(ary, CLArray):
             # pyopencl represents 0-long arrays' base_data as None
-            assert isinstance(ary.base_data, CLBuffer) or (ary.base_data is None)
+            assert (isinstance(ary.base_data, MemoryObjectHolder)
+                    or (ary.base_data is None))
             return (
                     None if ary.base_data is None else ary.base_data.int_ptr,
                     ary.offset,