diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index 53e90c335834..e6fc8fcb071a 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:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		raise RuntimeError('not implemented!')
 
 
@@ -112,7 +112,7 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		kernel_path = os.path.join(build_dir, self._kernel_path)
 		qemu_command = ['qemu-system-' + self._qemu_arch,
 				'-nodefaults',
@@ -141,7 +141,7 @@ class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		"""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/kunit_printer.py b/tools/testing/kunit/kunit_printer.py
index 5f1cc55ecdf5..015adf87dc2c 100644
--- a/tools/testing/kunit/kunit_printer.py
+++ b/tools/testing/kunit/kunit_printer.py
@@ -15,7 +15,7 @@ _RESET = '\033[0;0m'
 class Printer:
 	"""Wraps a file object, providing utilities for coloring output, etc."""
 
-	def __init__(self, output: typing.IO):
+	def __init__(self, output: typing.IO[str]):
 		self._output = output
 		self._use_color = output.isatty()
 
diff --git a/tools/testing/kunit/run_checks.py b/tools/testing/kunit/run_checks.py
index 066e6f938f6d..61cece1684df 100755
--- a/tools/testing/kunit/run_checks.py
+++ b/tools/testing/kunit/run_checks.py
@@ -37,7 +37,7 @@ def main(argv: Sequence[str]) -> None:
 	if argv:
 		raise RuntimeError('This script takes no arguments')
 
-	future_to_name: Dict[futures.Future, str] = {}
+	future_to_name: Dict[futures.Future[None], str] = {}
 	executor = futures.ThreadPoolExecutor(max_workers=len(commands))
 	for name, argv in commands.items():
 		if name in necessary_deps and shutil.which(necessary_deps[name]) is None: