diff --git a/containers/jug/dev.Dockerfile b/containers/jug/dev.Dockerfile
index e77f492ca251fc6c03070e4a0c3684495d1444b4..60a38c234aea0f52a8d4f57205300b97b29ccc14 100644
--- a/containers/jug/dev.Dockerfile
+++ b/containers/jug/dev.Dockerfile
@@ -159,7 +159,7 @@ make --jobs ${jobs} --keep-going --directory /opt/spack-environment \
   BUILDCACHE_OCI_FINAL="ghcr"
 spack find --long --no-groups \
 | sed -e '1,/Installed packages/d;s/\([^@]*\).*/\1/g' \
-| uniq -D -f1 | grep -v -w epic \
+| uniq -D -f1 | grep -v -w -e "\(epic\|py-pip\|py-cython\)" \
 | tee /tmp/duplicates.txt
 test -s /tmp/duplicates.txt && ( cat /tmp/duplicates.txt | while read hash spec ; do spack spec --long /${hash} ; done ) && exit 1
 ccache --show-stats