diff --git a/environments/key4hep-common/packages.yaml b/environments/key4hep-common/packages.yaml
index bee2f24e..a3dd0bc3 100644
--- a/environments/key4hep-common/packages.yaml
+++ b/environments/key4hep-common/packages.yaml
@@ -113,6 +113,7 @@ packages:
   lcio:
     variants: cxxstd=20
   pythia8:
+    require: +gzip
     variants: cxxstd=20
   sio:
     variants: cxxstd=20