diff --git a/src/ctapipe/core/provenance.py b/src/ctapipe/core/provenance.py
index 02ee888ab75..b30886317d4 100644
--- a/src/ctapipe/core/provenance.py
+++ b/src/ctapipe/core/provenance.py
@@ -306,7 +306,7 @@ def provenance(self):
 def _get_python_packages():
     return [
         {"name": p.name, "version": p.version}
-        for p in sorted(distributions(), key=lambda d: d.name)
+        for p in sorted(distributions(), key=lambda d: (d.name or "").lower())
     ]