diff --git a/setup.cfg b/setup.cfg
index 684c986..759bfdf 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -12,13 +12,17 @@ classifiers =
     License :: OSI Approved :: BSD License
     Operating System :: OS Independent
 [options]
-packages = heparchy
+packages =
+    heparchy
+    heparchy.data
+    heparchy.read
+    heparchy.write
 install_requires =
     attrs >=21
     numpy
     vector
     networkx
-    pyhepmc_ng
+    pyhepmc-ng ==0.4.3
     h5py
     pandas
     typicle