diff --git a/.github/workflows/tox.yaml b/.github/workflows/tox.yaml
index 0d019688..65c1f7f7 100644
--- a/.github/workflows/tox.yaml
+++ b/.github/workflows/tox.yaml
@@ -63,6 +63,7 @@ jobs:
           - juju_channel: 3.4/stable
             snap_install_flags: ""
             pip_constraints: constraints-juju34.txt
+            juju3: 1
     env:
       TEST_ZAZA_BUG_LP1987332: "on"  # http://pad.lv/1987332
     needs: build
@@ -97,6 +98,7 @@ jobs:
         set -euxo pipefail
         mkdir logs
         export PIP_CONSTRAINTS=$(pwd)/${{ matrix.pip_constraints }}
+        export TEST_JUJU3=${{ matrix.juju3 }}
         tox -e func-target -- ${{ matrix.bundle }} | tee logs/tox-output.txt
     - name: crashdump on failure
       if: failure()