diff --git a/.basedpyright/baseline.json b/.basedpyright/baseline.json
index d28fde67..16b09c48 100644
--- a/.basedpyright/baseline.json
+++ b/.basedpyright/baseline.json
@@ -59,14 +59,6 @@
             }
         ],
         "./pytools/__init__.py": [
-            {
-                "code": "reportImportCycles",
-                "range": {
-                    "startColumn": 0,
-                    "endColumn": 0,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportInvalidTypeVarUse",
                 "range": {
@@ -627,14 +619,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -699,14 +683,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 20,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -787,14 +763,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 14,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -835,14 +803,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 14,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -923,30 +883,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportUnannotatedClassAttribute",
-                "range": {
-                    "startColumn": 13,
-                    "endColumn": 25,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportIncompatibleMethodOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnsafeMultipleInheritance",
                 "range": {
@@ -2059,14 +1995,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 32,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -4827,14 +4755,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownMemberType",
                 "range": {
@@ -6723,14 +6643,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -6747,14 +6659,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -7886,8 +7790,8 @@
             {
                 "code": "reportUnreachable",
                 "range": {
-                    "startColumn": 16,
-                    "endColumn": 83,
+                    "startColumn": 12,
+                    "endColumn": 58,
                     "lineCount": 1
                 }
             }
@@ -8677,14 +8581,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownArgumentType",
                 "range": {
@@ -9081,14 +8977,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -9225,14 +9113,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -9339,14 +9219,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -10325,14 +10197,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 19,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -10389,14 +10253,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 19,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -10921,14 +10777,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownArgumentType",
                 "range": {
@@ -10985,14 +10833,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownArgumentType",
                 "range": {
@@ -11081,14 +10921,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownArgumentType",
                 "range": {
@@ -11153,14 +10985,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownParameterType",
                 "range": {
@@ -15217,6 +15041,22 @@
                     "lineCount": 1
                 }
             },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 28,
+                    "endColumn": 46,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportAttributeAccessIssue",
+                "range": {
+                    "startColumn": 30,
+                    "endColumn": 46,
+                    "lineCount": 1
+                }
+            },
             {
                 "code": "reportUnknownMemberType",
                 "range": {
@@ -15273,22 +15113,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 19,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -15297,14 +15121,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportIncompatibleMethodOverride",
                 "range": {
@@ -15313,14 +15129,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -15345,14 +15153,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 14,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -15377,14 +15177,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -15409,14 +15201,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownMemberType",
                 "range": {
@@ -15434,10 +15218,18 @@
                 }
             },
             {
-                "code": "reportImplicitOverride",
+                "code": "reportUnknownMemberType",
                 "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
+                    "startColumn": 23,
+                    "endColumn": 41,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportAttributeAccessIssue",
+                "range": {
+                    "startColumn": 25,
+                    "endColumn": 41,
                     "lineCount": 1
                 }
             },
@@ -15481,38 +15273,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 13,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -15603,46 +15363,6 @@
             }
         ],
         "./pytools/prefork.py": [
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 18,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 27,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -15755,30 +15475,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 18,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 27,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportReturnType",
                 "range": {
@@ -15787,22 +15483,6 @@
                     "lineCount": 2
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 15,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -16101,14 +15781,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 20,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -16573,14 +16245,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 20,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnknownVariableType",
                 "range": {
@@ -18059,22 +17723,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 14,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportUnusedParameter",
                 "range": {
@@ -18083,22 +17731,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 14,
-                    "lineCount": 1
-                }
-            },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 16,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -18247,27 +17879,35 @@
                     "lineCount": 1
                 }
             },
+            {
+                "code": "reportUnreachable",
+                "range": {
+                    "startColumn": 4,
+                    "endColumn": 18,
+                    "lineCount": 16
+                }
+            },
             {
                 "code": "reportUnreachable",
                 "range": {
                     "startColumn": 8,
-                    "endColumn": 57,
+                    "endColumn": 14,
                     "lineCount": 1
                 }
             },
             {
-                "code": "reportOptionalMemberAccess",
+                "code": "reportUnreachable",
                 "range": {
-                    "startColumn": 14,
-                    "endColumn": 15,
-                    "lineCount": 1
+                    "startColumn": 8,
+                    "endColumn": 18,
+                    "lineCount": 3
                 }
             },
             {
-                "code": "reportUnusedClass",
+                "code": "reportUnreachable",
                 "range": {
-                    "startColumn": 14,
-                    "endColumn": 22,
+                    "startColumn": 12,
+                    "endColumn": 18,
                     "lineCount": 1
                 }
             }
@@ -19189,14 +18829,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportImplicitOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 20,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportAny",
                 "range": {
@@ -21617,14 +21249,6 @@
                     "lineCount": 1
                 }
             },
-            {
-                "code": "reportIncompatibleMethodOverride",
-                "range": {
-                    "startColumn": 8,
-                    "endColumn": 12,
-                    "lineCount": 1
-                }
-            },
             {
                 "code": "reportImplicitOverride",
                 "range": {
diff --git a/pyproject.toml b/pyproject.toml
index bb8ca525..918f05a0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,9 +43,6 @@ test = [
     "pytest",
     "ruff",
 ]
-siphash = [
-    "siphash24>=1.6",
-]
 
 [project.urls]
 Documentation = "https://documen.tician.de/pytools/"
@@ -112,6 +109,12 @@ reportUnnecessaryIsInstance = "none"
 reportUnusedCallResult = "none"
 reportExplicitAny = "none"
 
+# This reports even cycles that are qualified by 'if TYPE_CHECKING'. Not what
+# we care about at this moment.
+# https://github.com/microsoft/pyright/issues/746
+reportImportCycles = "none"
+pythonVersion = "3.10"
+pythonPlatform = "All"
 
 [tool.mypy]
 python_version = "3.10"
diff --git a/pytools/__init__.py b/pytools/__init__.py
index 5440d01d..44c7ad6e 100644
--- a/pytools/__init__.py
+++ b/pytools/__init__.py
@@ -57,7 +57,7 @@
     cast,
 )
 
-from typing_extensions import Self, dataclass_transform
+from typing_extensions import Self, dataclass_transform, override
 
 from pytools.version import VERSION_TEXT
 
@@ -441,6 +441,7 @@ def get_copy_kwargs(self, **kwargs):
     def copy(self, **kwargs):
         return self.__class__(**self.get_copy_kwargs(**kwargs))
 
+    @override
     def __repr__(self):
         return "{}({})".format(
                 self.__class__.__name__,
@@ -483,23 +484,28 @@ def __setstate__(self, valuedict):
             fields.add(key)
             setattr(self, key, value)
 
+    @override
     def __eq__(self, other):
         if self is other:
             return True
         return (self.__class__ == other.__class__
                 and self.__getstate__() == other.__getstate__())
 
+    @override
     def __ne__(self, other):
         return not self.__eq__(other)
 
 
 class ImmutableRecordWithoutPickling(RecordWithoutPickling):
     """Hashable record. Does not explicitly enforce immutability."""
+    _cached_hash: int | None
+
     def __init__(self, *args, **kwargs):
         RecordWithoutPickling.__init__(self, *args, **kwargs)
         self._cached_hash = None
 
-    def __hash__(self):
+    @override
+    def __hash__(self) -> int:
         # This attribute may vanish during pickling.
         if getattr(self, "_cached_hash", None) is None:
             self._cached_hash = hash((
@@ -507,6 +513,7 @@ def __hash__(self):
                     *(getattr(self, field) for field in self.__class__.fields)
                     ))
 
+        assert self._cached_hash is not None
         return self._cached_hash
 
 
@@ -876,6 +883,7 @@ class keyed_memoize_method(keyed_memoize_on_first_arg):  # noqa: N801
         Can memoize methods on classes that do not allow setting attributes
         (e.g. by overwriting ``__setattr__``), e.g. frozen :mod:`dataclasses`.
     """
+    @override
     def _default_cache_dict_name(self, function):
         return intern(f"_memoize_dic_{function.__name__}")
 
@@ -1631,6 +1639,7 @@ def _get_column_widths(self, rows) -> tuple[int, ...]:
             max(len(row[i]) for row in rows) for i in range(self.ncolumns)
             )
 
+    @override
     def __str__(self) -> str:
         """
         Returns a string representation of the table.
@@ -2499,10 +2508,12 @@ def done(self):
         self.wall_elapsed = time.perf_counter() - self.perf_counter_start
         self.process_elapsed = time.process_time() - self.process_time_start
 
+    @override
     def __str__(self):
         cpu = self.process_elapsed / self.wall_elapsed
         return f"{self.wall_elapsed:.2f}s wall {cpu:.2f}x CPU"
 
+    @override
     def __repr__(self):
         wall = self.wall_elapsed
         process = self.process_elapsed
diff --git a/pytools/batchjob.py b/pytools/batchjob.py
index 84235a6c..a9790520 100644
--- a/pytools/batchjob.py
+++ b/pytools/batchjob.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing_extensions import override
+
 
 def _cp(src, dest):
     from pytools import assert_not_a_file
@@ -134,6 +136,7 @@ def arg(self, i):
     def kwarg(self, name):
         return self.kwargs[name]
 
+    @override
     def __str__(self):
         return "{}({})".format(self.classname,
                 ",".join(
diff --git a/pytools/convergence.py b/pytools/convergence.py
index 0b6ae0e7..56e1267d 100644
--- a/pytools/convergence.py
+++ b/pytools/convergence.py
@@ -10,6 +10,7 @@
 import numbers
 
 import numpy as np
+from typing_extensions import override
 
 
 # {{{ eoc estimation --------------------------------------------------------------
@@ -141,6 +142,7 @@ def pretty_print(self, *,
             return tbl.csv()
         raise ValueError(f"unknown table type: {table_type}")
 
+    @override
     def __str__(self):
         return self.pretty_print()
 
@@ -211,6 +213,7 @@ def add_data_point(self, order, error):
         self.orders.append(order)
         self.errors.append(error)
 
+    @override
     def __str__(self):
         from pytools import Table
         tbl = Table()
diff --git a/pytools/datatable.py b/pytools/datatable.py
index 7f34e3e6..126ed4ba 100644
--- a/pytools/datatable.py
+++ b/pytools/datatable.py
@@ -1,20 +1,22 @@
+"""
+An in-memory relational database table
+======================================
+
+.. autoclass:: DataTable
+"""
+
 from __future__ import annotations
 
 from typing import IO, TYPE_CHECKING, Any
 
+from typing_extensions import override
+
 from pytools import Record
 
 
 if TYPE_CHECKING:
     from collections.abc import Callable, Iterator, Sequence
 
-__doc__ = """
-An in-memory relational database table
-======================================
-
-.. autoclass:: DataTable
-"""
-
 
 class Row(Record):
     pass
@@ -58,6 +60,7 @@ def __len__(self) -> int:
     def __iter__(self) -> Iterator[list[Any]]:
         return self.data.__iter__()
 
+    @override
     def __str__(self) -> str:
         """Return a pretty-printed version of the table."""
 
diff --git a/pytools/debug.py b/pytools/debug.py
index 0fc125c8..14f900dd 100644
--- a/pytools/debug.py
+++ b/pytools/debug.py
@@ -3,6 +3,8 @@
 import contextlib
 import sys
 
+from typing_extensions import override
+
 from pytools import memoize
 
 
@@ -177,10 +179,12 @@ def __init__(self, source_dicts, target_dict):
 
         self.target_dict = target_dict
 
+    @override
     def __setitem__(self, key, value):
         dict.__setitem__(self, key, value)
         self.target_dict[key] = value
 
+    @override
     def __delitem__(self, key):
         dict.__delitem__(self, key)
         del self.target_dict[key]
diff --git a/pytools/lex.py b/pytools/lex.py
index d6844243..f77c60b4 100644
--- a/pytools/lex.py
+++ b/pytools/lex.py
@@ -2,12 +2,15 @@
 
 import re
 
+from typing_extensions import override
+
 
 class RuleError(RuntimeError):
     def __init__(self, rule):
         RuntimeError.__init__(self)
         self.Rule = rule
 
+    @override
     def __str__(self):
         return repr(self.Rule)
 
@@ -18,6 +21,7 @@ def __init__(self, s, str_index):
         self.string = s
         self.index = str_index
 
+    @override
     def __str__(self):
         return "at index {}: ...{}...".format(
                 self.index, self.string[self.index:self.index+20])
@@ -30,6 +34,7 @@ def __init__(self, msg, s, token):
         self.string = s
         self.Token = token
 
+    @override
     def __str__(self):
         if self.Token is None:
             return f"{self.message} at end of input"
@@ -43,6 +48,7 @@ def __init__(self, s: str, flags: int = 0) -> None:
         self.Content = s
         self.RE = re.compile(s, flags)
 
+    @override
     def __repr__(self) -> str:
         return f"RE({self.Content})"
 
diff --git a/pytools/persistent_dict.py b/pytools/persistent_dict.py
index 3f62425e..0f24967c 100644
--- a/pytools/persistent_dict.py
+++ b/pytools/persistent_dict.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from typing_extensions import override
+
 
 """Generic persistent, concurrent dictionary-like facility."""
 
@@ -573,6 +575,7 @@ def _make_container_dir(self) -> None:
         """Create the container directory to store the dictionary."""
         os.makedirs(self.container_dir, exist_ok=True)
 
+    @override
     def __getitem__(self, key: K) -> V:
         """Return the value associated with *key* in the dictionary."""
         return self.fetch(key)
@@ -581,26 +584,31 @@ def __setitem__(self, key: K, value: V) -> None:
         """Store (*key*, *value*) in the dictionary."""
         self.store(key, value)
 
+    @override
     def __len__(self) -> int:
         """Return the number of entries in the dictionary."""
         result, = next(self._exec_sql("SELECT COUNT(*) FROM dict"))
         assert isinstance(result, int)
         return result
 
+    @override
     def __iter__(self) -> Iterator[K]:
         """Return an iterator over the keys in the dictionary."""
         return self.keys()
 
+    @override
     def keys(self) -> Iterator[K]:  # type: ignore[override]
         """Return an iterator over the keys in the dictionary."""
         for row in self._exec_sql("SELECT key_value FROM dict ORDER BY rowid"):
             yield pickle.loads(row[0])[0]
 
+    @override
     def values(self) -> Iterator[V]:  # type: ignore[override]
         """Return an iterator over the values in the dictionary."""
         for row in self._exec_sql("SELECT key_value FROM dict ORDER BY rowid"):
             yield pickle.loads(row[0])[1]
 
+    @override
     def items(self) -> Iterator[tuple[K, V]]:  # type: ignore[override]
         """Return an iterator over the items in the dictionary."""
         for row in self._exec_sql("SELECT key_value FROM dict ORDER BY rowid"):
@@ -614,6 +622,7 @@ def nbytes(self) -> int:
 
         return result
 
+    @override
     def __repr__(self) -> str:
         """Return a string representation of the dictionary."""
         return f"{type(self).__name__}({self.filename}, nitems={len(self)})"
@@ -690,6 +699,7 @@ def clear_in_mem_cache(self) -> None:
         """
         self._fetch.cache_clear()
 
+    @override
     def store(self, key: K, value: V, _skip_if_present: bool = False) -> None:
         keyhash = self.key_builder(key)
         v = pickle.dumps((key, value))
@@ -730,6 +740,7 @@ def fetch_inner() -> tuple[Any] | None:
         key, value = pickle.loads(row[0])
         return key, value
 
+    @override
     def fetch(self, key: K) -> V:
         keyhash = self.key_builder(key)
 
@@ -741,6 +752,7 @@ def fetch(self, key: K) -> V:
             self._collision_check(key, stored_key)
             return value
 
+    @override
     def clear(self) -> None:
         super().clear()
         self._fetch.cache_clear()
@@ -796,6 +808,7 @@ def __init__(self,
                          enable_wal=enable_wal,
                          safe_sync=safe_sync)
 
+    @override
     def store(self, key: K, value: V, _skip_if_present: bool = False) -> None:
         keyhash = self.key_builder(key)
         v = pickle.dumps((key, value))
@@ -805,6 +818,7 @@ def store(self, key: K, value: V, _skip_if_present: bool = False) -> None:
         self._exec_sql(f"INSERT OR {mode} INTO dict VALUES (?, ?)",
                               (keyhash, v))
 
+    @override
     def fetch(self, key: K) -> V:
         keyhash = self.key_builder(key)
 
diff --git a/pytools/prefork.py b/pytools/prefork.py
index 14cca3f6..574d8ef7 100644
--- a/pytools/prefork.py
+++ b/pytools/prefork.py
@@ -26,6 +26,8 @@
 from subprocess import Popen
 from typing import TYPE_CHECKING, Any
 
+from typing_extensions import override
+
 
 if TYPE_CHECKING:
     from collections.abc import Sequence
@@ -65,6 +67,7 @@ def __init__(self) -> None:
         self.apids: dict[int, Popen[bytes]] = {}
         self.count: int = 0
 
+    @override
     def call(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
         from subprocess import call as spcall
 
@@ -74,6 +77,7 @@ def call(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
             raise ExecError(
                     "error invoking '{}': {}".format(" ".join(cmdline), e)) from e
 
+    @override
     def call_async(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
         try:
             self.count += 1
@@ -86,6 +90,7 @@ def call_async(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
             raise ExecError(
                 "error invoking '{}': {}".format(" ".join(cmdline), e)) from e
 
+    @override
     def call_capture_output(self,
                             cmdline: Sequence[str],
                             cwd: str | None = None,
@@ -108,12 +113,14 @@ def call_capture_output(self,
             raise ExecError(
                     "error invoking '{}': {}".format(" ".join(cmdline), e)) from e
 
+    @override
     def wait(self, aid: int) -> int:
         proc = self.apids.pop(aid)
         retc = proc.wait()
 
         return retc
 
+    @override
     def waitall(self) -> dict[int, int]:
         rets = {}
 
@@ -225,18 +232,21 @@ def _quit(self) -> None:
         from os import waitpid
         waitpid(self.server_pid, 0)
 
+    @override
     def call(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
         result = self._remote_invoke("call", cmdline, cwd)
 
         assert isinstance(result, int)
         return result
 
+    @override
     def call_async(self, cmdline: Sequence[str], cwd: str | None = None) -> int:
         result = self._remote_invoke("call_async", cmdline, cwd)
 
         assert isinstance(result, int)
         return result
 
+    @override
     def call_capture_output(self,
                             cmdline: Sequence[str],
                             cwd: str | None = None,
@@ -245,12 +255,14 @@ def call_capture_output(self,
         return self._remote_invoke("call_capture_output", cmdline, cwd,  # type: ignore[return-value]
                                    error_on_nonzero)
 
+    @override
     def wait(self, aid: int) -> int:
         result = self._remote_invoke("wait", aid)
 
         assert isinstance(result, int)
         return result
 
+    @override
     def waitall(self) -> dict[int, int]:
         result = self._remote_invoke("waitall")
 
diff --git a/pytools/tag.py b/pytools/tag.py
index 70d15515..d1b43ef4 100644
--- a/pytools/tag.py
+++ b/pytools/tag.py
@@ -30,7 +30,7 @@
 from typing import TYPE_CHECKING, Any, TypeVar
 from warnings import warn
 
-from typing_extensions import Self, dataclass_transform
+from typing_extensions import Self, dataclass_transform, override
 
 from pytools import memoize, memoize_method
 
@@ -101,9 +101,11 @@ def from_class(cls, argcls: Any) -> DottedName:
                              "start with double underscores")
         return cls(name_parts)
 
+    @override
     def __repr__(self) -> str:
         return self.__class__.__name__ + repr(self.name_parts)
 
+    @override
     def __eq__(self, other: object) -> bool:
         if isinstance(other, DottedName):
             return self.name_parts == other.name_parts
@@ -253,11 +255,10 @@ def __init__(self, tags: frozenset[Tag] = frozenset()):
     # ReST references in docstrings must be fully qualified, as docstrings may
     # be inherited and appear in different contexts.
 
-    # type-checking only so that self.tags = ... in subclasses still works
-    if TYPE_CHECKING:
-        @property
-        def tags(self) -> frozenset[Tag]:
-            ...
+    # Before https://peps.python.org/pep-0767/, there isn't a good way to declare
+    # an attribute read-only. Mypy accepts @property, but this is unsound:
+    # https://peps.python.org/pep-0767/#clarifying-interaction-of-property-and-protocols
+    tags: frozenset[Tag]  # pyright: ignore[reportUninitializedInstanceVariable]
 
     def _with_new_tags(self, tags: frozenset[Tag]) -> Self:
         """
@@ -324,11 +325,13 @@ def tags_not_of_type(self, tag_t: type[TagT]) -> frozenset[Tag]:
                          for tag in self.tags
                          if not isinstance(tag, tag_t)})
 
+    @override
     def __eq__(self, other: object) -> bool:
         if isinstance(other, Taggable):
             return self.tags == other.tags
         return super().__eq__(other)
 
+    @override
     def __hash__(self) -> int:
         return hash(self.tags)