diff --git a/keyrings/__init__.py b/keyrings/__init__.py
index 0d1f7ed..69e3be5 100644
--- a/keyrings/__init__.py
+++ b/keyrings/__init__.py
@@ -1 +1 @@
-__path__ = __import__('pkgutil').extend_path(__path__, __name__)  # type: ignore
+__path__ = __import__('pkgutil').extend_path(__path__, __name__)
diff --git a/keyrings/alt/Gnome.py b/keyrings/alt/Gnome.py
index 1ab5900..6f5dd76 100644
--- a/keyrings/alt/Gnome.py
+++ b/keyrings/alt/Gnome.py
@@ -2,7 +2,9 @@
     import gi
 
     gi.require_version('GnomeKeyring', '1.0')
-    from gi.repository import GnomeKeyring
+    from gi.repository import (  # type: ignore[attr-defined] # Missing from PyGObject-stubs
+        GnomeKeyring,
+    )
 except (ImportError, ValueError, AttributeError):
     pass
 
diff --git a/keyrings/alt/_win_crypto.py b/keyrings/alt/_win_crypto.py
index 6d02c7e..53a2db0 100644
--- a/keyrings/alt/_win_crypto.py
+++ b/keyrings/alt/_win_crypto.py
@@ -1,4 +1,17 @@
-from ctypes import (
+import os
+import sys
+
+if os.name != "nt":
+    raise ImportError(
+        "Module " + __name__ + " can only be imported on nt platforms. Not " + os.name
+    )
+
+# if TYPE_CHECKING:
+# python/mypy#8166
+# python/typing#1732
+assert sys.platform == "win32"
+
+from ctypes import (  # noqa: E402
     POINTER,
     WINFUNCTYPE,
     Structure,
@@ -10,14 +23,9 @@
     create_string_buffer,
     memmove,
     windll,
+    wintypes,
 )
 
-try:
-    from ctypes import wintypes
-except ValueError:
-    # see http://bugs.python.org/issue16396
-    raise ImportError("wintypes")
-
 # Crypto API ctypes bindings
 
 
diff --git a/keyrings/alt/file.py b/keyrings/alt/file.py
index 8d0bfed..bcce681 100644
--- a/keyrings/alt/file.py
+++ b/keyrings/alt/file.py
@@ -14,7 +14,7 @@
 class PlaintextKeyring(Keyring):
     """Simple File Keyring with no encryption"""
 
-    priority = 0.5  # type: ignore
+    priority = 0.5  # type: ignore[assignment] # jaraco.classes.properties.classproperty isn't seen as a property
     "Applicable for all platforms, but not recommended"
 
     filename = 'keyring_pass.cfg'
diff --git a/mypy.ini b/mypy.ini
index 2241eb9..5e1fe12 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -13,6 +13,15 @@ explicit_package_bases = True
 # Disable overload-overlap due to many false-positives
 disable_error_code = overload-overlap
 
-# workaround for realpython/pytest-mypy#160
-[mypy-keyrings.alt._win_crypto]
-ignore_errors = True
+# gdata is archived since 2022, last update in 2016
+# it installs but doesn't import on Python 3
+# https://github.com/google/gdata-python-client/issues/29
+# https://github.com/google/gdata-python-client/issues/65
+[mypy-gdata.*]
+ignore_missing_imports = True
+
+# Keyczar is deprecated in favor of Tink as of 2019. Archived since 2022.
+# python-keyczar also doesn't install on Python 3
+# https://github.com/google/keyczar/issues/125
+[mypy-keyczar.*]
+ignore_missing_imports = True
diff --git a/pyproject.toml b/pyproject.toml
index 3deb4b4..c1beb68 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,9 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "keyrings.alt"
-authors = [
-	{ name = "Jason R. Coombs", email = "jaraco@jaraco.com" },
-]
+authors = [{ name = "Jason R. Coombs", email = "jaraco@jaraco.com" }]
 description = "Alternate keyring implementations"
 readme = "README.rst"
 classifiers = [
@@ -17,10 +15,7 @@ classifiers = [
 	"Programming Language :: Python :: 3 :: Only",
 ]
 requires-python = ">=3.8"
-dependencies = [
-	"jaraco.classes",
-	"jaraco.context",
-]
+dependencies = ["jaraco.classes", "jaraco.context"]
 dynamic = ["version"]
 
 [project.urls]
@@ -35,11 +30,14 @@ test = [
 	"keyring >= 20",
 	"pycryptodomex",
 	"pycryptodome",
-	# gdata doesn't currently install on Python 3
-	# http://code.google.com/p/gdata-python-client/issues/detail?id=229
+	# gdata is archived since 2022, last update in 2016
+	# it installs but doesn't import on Python 3
+	# https://github.com/google/gdata-python-client/issues/29
+	# https://github.com/google/gdata-python-client/issues/65
 	'gdata; python_version=="2.7"',
-	# keyczar doesn't currently install on Python 3.
-	# http://code.google.com/p/keyczar/issues/detail?id=125
+	# Keyczar is deprecated in favor of Tink as of 2019. Archived since 2022.
+	# python-keyczar also doesn't install on Python 3
+	# https://github.com/google/keyczar/issues/125
 	'python-keyczar; python_version=="2.7"',
 ]
 
@@ -57,24 +55,18 @@ doc = [
 	# local
 ]
 
-check = [
-	"pytest-checkdocs >= 2.4",
-	"pytest-ruff >= 0.2.1; sys_platform != 'cygwin'",
-]
+check = ["pytest-checkdocs >= 2.4", "pytest-ruff >= 0.2.1; sys_platform != 'cygwin'"]
 
-cover = [
-	"pytest-cov",
-]
+cover = ["pytest-cov"]
 
-enabler = [
-	"pytest-enabler >= 2.2",
-]
+enabler = ["pytest-enabler >= 2.2"]
 
 type = [
 	# upstream
 	"pytest-mypy",
 
 	# local
+	"PyGObject-stubs",
 ]
 
 
@@ -88,7 +80,3 @@ multi = "keyrings.alt.multi"
 
 
 [tool.setuptools_scm]
-
-
-[tool.pytest-enabler.mypy]
-# Disabled due to jaraco/skeleton#143
diff --git a/tests/test_multi.py b/tests/test_multi.py
index 3cf978b..f21d490 100644
--- a/tests/test_multi.py
+++ b/tests/test_multi.py
@@ -10,7 +10,7 @@ class MultipartKeyringWrapperTestCase(unittest.TestCase):
     """Test the wrapper that breaks passwords into smaller chunks"""
 
     class MockKeyring(KeyringBackend):
-        priority = 1  # type: ignore
+        priority = 1  # type: ignore[assignment] # jaraco.classes.properties.classproperty isn't seen as a property
 
         def __init__(self):
             self.passwords = {}