diff --git a/setup.py b/setup.py
index 136726d..9f55e76 100644
--- a/setup.py
+++ b/setup.py
@@ -24,5 +24,6 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Environment :: Console',
         'Topic :: Scientific/Engineering :: Astronomy'
-    ]
+    ],
+    python_requires='>=3.7'
 )