diff --git a/setup.cfg b/setup.cfg
index 2237267d1185a249d279037eead25b095fe6a91d..6cb9c696385b9cb94dfc7f6ddbf866d9b59c0865 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,3 +1,5 @@
+# https://setuptools.readthedocs.io/en/latest/userguide/declarative_config.html
+
 [aliases]
 test=pytest
 
@@ -46,6 +48,7 @@ project_urls =
 
 [options]
 packages = find:
+include_package_data = True
 python_requires = >=3.6
 install_requires =
     h5py
@@ -56,7 +59,9 @@ install_requires =
     scipy
 tests_require =
     PyPDF2
-include_package_data = True
+
+[options.extras_require]
+range = inspiral-range
 
 [options.entry_points]
 console_scripts =