diff --git a/.zuul.yaml b/.zuul.yaml
index e11445f79..34c6f8727 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -64,7 +64,7 @@
         TEMPEST_PLUGINS: '"/opt/stack/congress-tempest-plugin /opt/stack/telemetry-tempest-plugin /opt/stack/murano-tempest-plugin /opt/stack/heat-tempest-plugin /opt/stack/mistral-tempest-plugin /opt/stack/monasca-tempest-plugin"'
         CONGRESS_MULTIPROCESS_DEPLOYMENT: true
         CONGRESS_EXPOSE_ENCRYPTION_KEY_FOR_TEST: true
-        ENABLE_CONGRESS_Z3: false
+        ENABLE_CONGRESS_Z3: true
         USE_Z3_RELEASE: 4.7.1
 
 - job:
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index b7d3ccd1e..c5acaf5ce 100755
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -151,6 +151,11 @@ function _install_z3 {
         pushd $CONGRESS_Z3_DIR
         z3rel="z3-${USE_Z3_RELEASE}"
         z3file="${z3rel}-x64-${os_VENDOR,,}-${os_RELEASE}"
+        # binary not available for ubuntu-18, so use ubuntu-16 binary instead
+        if [ ${os_VENDOR,,} == "ubuntu" ] && [ ${os_RELEASE} == "18.04" ]; then
+            z3file="${z3rel}-x64-ubuntu-16.04"
+            echo "WARNING: Using ${z3file} binary on ${os_VENDOR,,}-${os_RELEASE} because ${z3rel}-x64-${os_VENDOR,,}-${os_RELEASE} is not available."
+        fi
         url="https://github.com/Z3Prover/z3/releases/download/${z3rel}/${z3file}.zip"
         if [ ! -f "${z3file}.zip" ]; then
             wget "${url}" || true