diff --git a/docs/CHANGELOG.rst b/docs/CHANGELOG.rst
index cfbbfe12e..86d8bdbfe 100644
--- a/docs/CHANGELOG.rst
+++ b/docs/CHANGELOG.rst
@@ -14,6 +14,7 @@ Fix
 ---
 - Add default value for ``FLOW_PROCESSES_ALLOW_LIST`` and
   ``FLOW_PROCESSES_IGNORE_LIST`` in case of missing settings.
+- Fix null executor warnings
 
 
 ===================
diff --git a/resolwe/flow/executors/null/prepare.py b/resolwe/flow/executors/null/prepare.py
index 784d37bdb..d6f4ad50d 100644
--- a/resolwe/flow/executors/null/prepare.py
+++ b/resolwe/flow/executors/null/prepare.py
@@ -7,18 +7,8 @@
 :meth:`~resolwe.flow.executors.prepare.BaseFlowExecutorPreparer.extend_settings`
 method.
 """
-from resolwe.flow.models import Worker
-
 from ..prepare import BaseFlowExecutorPreparer  # noqa: F401
 
 
 class FlowExecutorPreparer(BaseFlowExecutorPreparer):
     """Specialized manager assist for the null executor."""
-
-    def prepare_for_execution(self, data):
-        """Prepare the data object for the execution.
-
-        Mark worker object as done.
-        """
-        data.worker.status = Worker.STATUS_COMPLETED
-        data.worker.save()
diff --git a/resolwe/flow/executors/null/run.py b/resolwe/flow/executors/null/run.py
index 40a88e3bf..4efbe6c85 100644
--- a/resolwe/flow/executors/null/run.py
+++ b/resolwe/flow/executors/null/run.py
@@ -20,5 +20,5 @@ class FlowExecutor(BaseFlowExecutor):
     name = "null"
 
     async def run(self):
-        """Do nothing :)."""
-        pass
+        """Notify listener run is completed."""
+        await self.communicator.finish({"rc": 0})
diff --git a/resolwe/flow/tests/test_executors.py b/resolwe/flow/tests/test_executors.py
index 6c7437262..98d105f1e 100644
--- a/resolwe/flow/tests/test_executors.py
+++ b/resolwe/flow/tests/test_executors.py
@@ -602,12 +602,11 @@ def test_docker_uid_gid(self):
         data = self.run_process("test-docker-uid-gid")
         self.assertEqual(data.output["result"], "OK")
 
-    @unittest.skip("Null executor test currently not working.")
     @with_null_executor
     @tag_process("test-save-number")
     def test_null_executor(self):
         data = self.run_process(
-            "test-save-number", {"number": 19}, assert_status=Data.STATUS_WAITING
+            "test-save-number", {"number": 19}, assert_status=Data.STATUS_DONE
         )
         self.assertEqual(data.input["number"], 19)
         self.assertEqual(data.output, {})