diff --git a/congress/datasources/datasource_driver.py b/congress/datasources/datasource_driver.py
index 44f77c09f..eec830172 100644
--- a/congress/datasources/datasource_driver.py
+++ b/congress/datasources/datasource_driver.py
@@ -1470,13 +1470,8 @@ class ExecutionDriver(object):
         self.executable_methods = {}
         self.LEADER_TIMEOUT = 5
         self._leader_node_id = None
-        # TODO(dse2): remove the if-conditional when DSE1 support ended
-        #   The conditional is temporarily present to support DSE1 services
-        #   that don't have heartbeat_callbacks.
-        if hasattr(self, 'heartbeat_callbacks'):
-            # defined in DataService class
-            self.heartbeat_callbacks[
-                'check_leader'] = self._check_leader_heartbeat
+        # defined in DataService class
+        self.heartbeat_callbacks['check_leader'] = self._check_leader_heartbeat
 
     def _check_leader_heartbeat(self):
         """Vacate leader if heartbeat lost"""
diff --git a/congress/tests/datasources/test_datasource_driver.py b/congress/tests/datasources/test_datasource_driver.py
index 496d74829..396dfd6bc 100644
--- a/congress/tests/datasources/test_datasource_driver.py
+++ b/congress/tests/datasources/test_datasource_driver.py
@@ -1899,10 +1899,21 @@ class TestPushedDriver(base.SqlTestCase):
 
 
 class TestExecutionDriver(base.TestCase):
+    class ExtendedExecutionDriver(datasource_driver.ExecutionDriver):
+        """Subclass of test target.
+
+        Execution Driver is an add-on class for datasource driver so
+        it's assumed to have heartbeat_callbacks variable defined in
+        DataService class.
+        """
+        def __init__(self):
+            # A variable defined in datasource_driver
+            self.heartbeat_callbacks = {}
+            super(TestExecutionDriver.ExtendedExecutionDriver, self).__init__()
 
     def setUp(self):
         super(TestExecutionDriver, self).setUp()
-        self.exec_driver = datasource_driver.ExecutionDriver()
+        self.exec_driver = TestExecutionDriver.ExtendedExecutionDriver()
 
     def test_get_method_nested(self):
         class server(object):