diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9df26d73..5ad401b5 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -64,3 +64,18 @@ repos:
     hooks:
       - id: check-hooks-apply
       - id: check-useless-excludes
+
+  - repo: local
+    hooks:
+      - id: annotations
+        name: Require "from __future__ import annotations"
+        language: pygrep
+        types: [python]
+        # exclude config-like files
+        exclude: "^(setup\\.py|doc/conf\\.py|openslide/_version\\.py)$"
+        # Allow files with import statement, or of less than two characters.
+        # One-character files are allowed because that's the best we can do
+        # with paired negative lookbehind and lookahead assertions.  ^ and $
+        # don't work because --multiline causes them to match at newlines.
+        entry: "(?<!.)(?!.)|\nfrom __future__ import annotations"
+        args: [--multiline, --negate]
diff --git a/doc/jekyll_fix.py b/doc/jekyll_fix.py
index a2b65128..b479e00e 100644
--- a/doc/jekyll_fix.py
+++ b/doc/jekyll_fix.py
@@ -23,6 +23,8 @@
 # deployed to the website.
 # Rename Sphinx output paths to drop the underscore.
 
+from __future__ import annotations
+
 import os
 
 from sphinx.util import logging
diff --git a/examples/deepzoom/deepzoom_multiserver.py b/examples/deepzoom/deepzoom_multiserver.py
index 267d8ee0..de0c2061 100755
--- a/examples/deepzoom/deepzoom_multiserver.py
+++ b/examples/deepzoom/deepzoom_multiserver.py
@@ -19,6 +19,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 from argparse import ArgumentParser
 import base64
 from collections import OrderedDict
diff --git a/examples/deepzoom/deepzoom_server.py b/examples/deepzoom/deepzoom_server.py
index aa492389..0b82aeda 100755
--- a/examples/deepzoom/deepzoom_server.py
+++ b/examples/deepzoom/deepzoom_server.py
@@ -19,6 +19,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 from argparse import ArgumentParser
 import base64
 from io import BytesIO
diff --git a/examples/deepzoom/deepzoom_tile.py b/examples/deepzoom/deepzoom_tile.py
index 68c1a3e3..aad834d9 100755
--- a/examples/deepzoom/deepzoom_tile.py
+++ b/examples/deepzoom/deepzoom_tile.py
@@ -21,6 +21,8 @@
 
 """An example program to generate a Deep Zoom directory tree from a slide."""
 
+from __future__ import annotations
+
 from argparse import ArgumentParser
 import base64
 from io import BytesIO
diff --git a/openslide/__init__.py b/openslide/__init__.py
index 61e60685..43c9f91c 100644
--- a/openslide/__init__.py
+++ b/openslide/__init__.py
@@ -23,6 +23,8 @@
 This package provides Python bindings for the OpenSlide library.
 """
 
+from __future__ import annotations
+
 from collections.abc import Mapping
 from io import BytesIO
 
diff --git a/openslide/deepzoom.py b/openslide/deepzoom.py
index 28ec7a81..66734d70 100644
--- a/openslide/deepzoom.py
+++ b/openslide/deepzoom.py
@@ -23,6 +23,8 @@
 OpenSlide objects.
 """
 
+from __future__ import annotations
+
 from io import BytesIO
 import math
 from xml.etree.ElementTree import Element, ElementTree, SubElement
diff --git a/openslide/lowlevel.py b/openslide/lowlevel.py
index 8ab11728..a4edb466 100644
--- a/openslide/lowlevel.py
+++ b/openslide/lowlevel.py
@@ -30,6 +30,8 @@
 rather than in the high-level interface.)
 """
 
+from __future__ import annotations
+
 from ctypes import (
     POINTER,
     byref,
diff --git a/tests/common.py b/tests/common.py
index 75e7a2dd..9efd1c26 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -17,6 +17,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 import os
 from pathlib import Path
 
diff --git a/tests/test_base.py b/tests/test_base.py
index 7fc983fa..bcced6f8 100644
--- a/tests/test_base.py
+++ b/tests/test_base.py
@@ -17,6 +17,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 import ctypes
 import unittest
 
@@ -35,13 +37,17 @@ def test_open_slide(self):
     def test_lowlevel_available(self):
         '''Ensure all exported functions have an 'available' attribute.'''
         for name in dir(lowlevel):
+            attr = getattr(lowlevel, name)
             # ignore classes and unexported functions
             if name.startswith('_') or name[0].isupper():
                 continue
+            # ignore __future__ imports
+            if getattr(attr, '__module__', None) == '__future__':
+                continue
             # ignore random imports
             if hasattr(ctypes, name) or name in ('count', 'platform'):
                 continue
             self.assertTrue(
-                hasattr(getattr(lowlevel, name), 'available'),
+                hasattr(attr, 'available'),
                 f'"{name}" missing "available" attribute',
             )
diff --git a/tests/test_deepzoom.py b/tests/test_deepzoom.py
index 4063ce86..af1cd503 100644
--- a/tests/test_deepzoom.py
+++ b/tests/test_deepzoom.py
@@ -17,6 +17,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 import unittest
 
 from common import file_path
diff --git a/tests/test_imageslide.py b/tests/test_imageslide.py
index d0e200c9..603cb72b 100644
--- a/tests/test_imageslide.py
+++ b/tests/test_imageslide.py
@@ -17,6 +17,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 import unittest
 
 from PIL import Image
diff --git a/tests/test_openslide.py b/tests/test_openslide.py
index f6c0e01f..7ee86363 100644
--- a/tests/test_openslide.py
+++ b/tests/test_openslide.py
@@ -17,6 +17,8 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
+from __future__ import annotations
+
 from ctypes import ArgumentError
 import re
 import sys