diff --git a/mistral/services/triggers.py b/mistral/services/triggers.py
index 9a98ff718..d1f4fac86 100644
--- a/mistral/services/triggers.py
+++ b/mistral/services/triggers.py
@@ -236,6 +236,9 @@ def on_workflow_complete(wf_ex):
     if wf_ex.task_execution_id:
         return
 
+    if not wf_ex.description:
+        return
+
     try:
         description = json.loads(wf_ex.description)
     except ValueError as e:
diff --git a/mistral/tests/unit/engine/test_execution_params.py b/mistral/tests/unit/engine/test_execution_params.py
new file mode 100644
index 000000000..c4c2c48ce
--- /dev/null
+++ b/mistral/tests/unit/engine/test_execution_params.py
@@ -0,0 +1,49 @@
+# Copyright 2018 - Nokia Networks
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    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.
+
+from oslo_config import cfg
+
+from mistral.db.v2 import api as db_api
+from mistral.services import workflows as wf_service
+from mistral.tests.unit.engine import base
+from mistral.workflow import states
+
+# Use the set_default method to set value otherwise in certain test cases
+# the change in value is not permanent.
+cfg.CONF.set_default('auth_enable', False, group='pecan')
+
+
+class TestExecutionParameters(base.EngineTestCase):
+
+    def test_null_description(self):
+        wf_text = """
+        version: '2.0'
+
+        wf:
+          tasks:
+            task1:
+              action: std.noop
+        """
+        wf_service.create_workflows(wf_text)
+
+        wf_ex = self.engine.start_workflow('wf', description=None)
+
+        self.await_workflow_success(wf_ex.id)
+
+        self.assertEqual(states.RUNNING, wf_ex.state)
+
+        with db_api.transaction():
+            wf_ex = db_api.get_workflow_execution(wf_ex.id)
+
+        self.assertEqual(states.SUCCESS, wf_ex.state)