diff --git a/extract_otp_secret_keys.py b/extract_otp_secret_keys.py
index 7aafcdc..ba5e339 100644
--- a/extract_otp_secret_keys.py
+++ b/extract_otp_secret_keys.py
@@ -41,6 +41,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+from __future__ import annotations  # for compatibility with Python < 3.11
 import argparse
 import base64
 import csv
diff --git a/setup.py b/setup.py
index 1b291aa..1514d72 100644
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,4 @@
+from __future__ import annotations  # for compatibility with Python < 3.11
 import pathlib
 from setuptools import setup  # type: ignore
 
diff --git a/test_extract_otp_secret_keys_pytest.py b/test_extract_otp_secret_keys_pytest.py
index 0e81543..5928833 100644
--- a/test_extract_otp_secret_keys_pytest.py
+++ b/test_extract_otp_secret_keys_pytest.py
@@ -18,6 +18,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+from __future__ import annotations  # for compatibility with Python < 3.11
 import io
 import os
 import pathlib
diff --git a/test_extract_otp_secret_keys_unittest.py b/test_extract_otp_secret_keys_unittest.py
index 6a2d836..1025597 100644
--- a/test_extract_otp_secret_keys_unittest.py
+++ b/test_extract_otp_secret_keys_unittest.py
@@ -18,6 +18,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+from __future__ import annotations  # for compatibility with Python < 3.11
 import io
 import os
 import sys
diff --git a/test_extract_qrcode_unittest.py b/test_extract_qrcode_unittest.py
index d7298ee..75a4342 100644
--- a/test_extract_qrcode_unittest.py
+++ b/test_extract_qrcode_unittest.py
@@ -18,6 +18,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+from __future__ import annotations  # for compatibility with Python < 3.11
 import unittest
 
 import extract_otp_secret_keys