diff --git a/unit_tests/__init__.py b/unit_tests/__init__.py
index 8203d13..7578bb5 100644
--- a/unit_tests/__init__.py
+++ b/unit_tests/__init__.py
@@ -11,3 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+# force zaza to not use threads for async
+import zaza
+
+zaza.RUN_LIBJUJU_IN_THREAD = False