diff --git a/wheelhouse.txt b/wheelhouse.txt
index bd63690..c3d35db 100644
--- a/wheelhouse.txt
+++ b/wheelhouse.txt
@@ -1,4 +1,5 @@
 # charmhelpers.contrib.openstack.cert_utils charms with certificates relation
+poetry-core  # needed to build dnspython.
 dnspython
 # charmhelpers.contrib.network all
 netifaces>=0.10.4