diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index f01f94106129..7f648802caf6 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -92,7 +92,7 @@ class LinuxSourceTreeOperations:
 		if stderr:  # likely only due to build warnings
 			print(stderr.decode())
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		raise RuntimeError('not implemented!')
 
 
@@ -113,7 +113,7 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		kernel_path = os.path.join(build_dir, self._kernel_path)
 		qemu_command = ['qemu-system-' + self._qemu_arch,
 				'-nodefaults',
@@ -142,7 +142,7 @@ class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		"""Runs the Linux UML binary. Must be named 'linux'."""
 		linux_bin = os.path.join(build_dir, 'linux')
 		params.extend(['mem=1G', 'console=tty', 'kunit_shutdown=halt'])
diff --git a/tools/testing/kunit/mypy.ini b/tools/testing/kunit/mypy.ini
new file mode 100644
index 000000000000..ddd288309efa
--- /dev/null
+++ b/tools/testing/kunit/mypy.ini
@@ -0,0 +1,6 @@
+[mypy]
+strict = True
+
+# E.g. we can't write subprocess.Popen[str] until Python 3.9+.
+# But kunit.py tries to support Python 3.7+, so let's disable it.
+disable_error_code = type-arg
diff --git a/tools/testing/kunit/run_checks.py b/tools/testing/kunit/run_checks.py
index 8208c3b3135e..c6d494ea3373 100755
--- a/tools/testing/kunit/run_checks.py
+++ b/tools/testing/kunit/run_checks.py
@@ -23,7 +23,7 @@ commands: Dict[str, Sequence[str]] = {
 	'kunit_tool_test.py': ['./kunit_tool_test.py'],
 	'kunit smoke test': ['./kunit.py', 'run', '--kunitconfig=lib/kunit', '--build_dir=kunit_run_checks'],
 	'pytype': ['/bin/sh', '-c', 'pytype *.py'],
-	'mypy': ['mypy', '--strict', '--exclude', '_test.py$', '--exclude', 'qemu_configs/', '.'],
+	'mypy': ['mypy', '--config-file', 'mypy.ini', '--exclude', '_test.py$', '--exclude', 'qemu_configs/', '.'],
 }
 
 # The user might not have mypy or pytype installed, skip them if so.