diff --git a/src/lib/charm/openstack/cinder_netapp.py b/src/lib/charm/openstack/cinder_netapp.py
index 464e87a..8016c65 100644
--- a/src/lib/charm/openstack/cinder_netapp.py
+++ b/src/lib/charm/openstack/cinder_netapp.py
@@ -51,10 +51,11 @@ class CinderNetAppCharm(
             ('netapp_password', cget('netapp-password')),
             ('volume_driver', volumedriver),
             ('volume_backend_name', service),
-            ('netapp_pool_name_search_pattern', cget(
-                'netapp-pool-name-search-pattern'))
         ]
-
+        pool_name_search_pattern = cget('netapp-pool-name-search-pattern')
+        if pool_name_search_pattern:
+            driver_options_common += [
+                ('netapp_pool_name_search_pattern', pool_name_search_pattern)]
         if cget('netapp-server-port') == 443:
             driver_transport = [
                 ('netapp_transport_type', "https")]
diff --git a/unit_tests/test_lib_charm_openstack_cinder_netapp.py b/unit_tests/test_lib_charm_openstack_cinder_netapp.py
index ab01d20..f93f4f7 100644
--- a/unit_tests/test_lib_charm_openstack_cinder_netapp.py
+++ b/unit_tests/test_lib_charm_openstack_cinder_netapp.py
@@ -79,6 +79,16 @@ class TestCinderNetAppCharm(test_utils.PatchHelper):
         self.assertIn(('nfs_shares_config',
                        econfig['netapp-nfs-shares-config']), config)
 
+    def test_cinder_unset_var(self):
+        econfig = {'netapp-storage-family': 'eseries',
+                   'netapp-controller-ips': '10.0.0.1',
+                   'netapp-array-password': 'abc123',
+                   'use-multipath': True}
+        charm = self._patch_config_and_charm(econfig)
+        config = charm.cinder_configuration()
+        keys = [c[0] for c in config]
+        self.assertNotIn('netapp_pool_name_search_pattern', keys)
+
     def test_cinder_iscsi_options(self):
         econfig = {'netapp-pool-name-search-pattern': 'foo.*bar',
                    'netapp-lun-space-reservation': True,