diff --git a/pyModeS/decoder/uncertainty.py b/pyModeS/decoder/uncertainty.py
index 122603a..00cf350 100644
--- a/pyModeS/decoder/uncertainty.py
+++ b/pyModeS/decoder/uncertainty.py
@@ -4,7 +4,12 @@
 
 from __future__ import annotations
 
-from typing import TypedDict
+import sys
+
+if sys.version_info < (3, 8):
+    from typing_extensions import TypedDict
+else:
+    from typing import TypedDict
 
 NA = None
 
diff --git a/setup.py b/setup.py
index f977af5..172cc0b 100644
--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,8 @@ details = dict(
     ],
     keywords="Mode-S ADS-B EHS ELS Comm-B",
     packages=find_packages(exclude=["contrib", "docs", "tests"]),
-    install_requires=["numpy", "pyzmq"],
+    # typing_extensions are no longer necessary after Python 3.8 (TypedDict)
+    install_requires=["numpy", "pyzmq", "typing_extensions"],
     extras_require={"fast": ["Cython"]},
     package_data={"pyModeS": ["*.pyx", "*.pxd", "py.typed"]},
     scripts=["pyModeS/streamer/modeslive"],