diff --git a/hot/software-config/elements/heat-config/bin/heat-config-notify b/hot/software-config/elements/heat-config/bin/heat-config-notify
index 2954860..eba1258 100755
--- a/hot/software-config/elements/heat-config/bin/heat-config-notify
+++ b/hot/software-config/elements/heat-config/bin/heat-config-notify
@@ -107,10 +107,10 @@ def main(argv=sys.argv, stdin=sys.stdin):
         str_signal_data = trim_response(signal_data)
         if sigverb == 'PUT':
             r = requests.put(sigurl, data=str_signal_data,
-                             headers={'content-type': None})
+                             headers={'content-type': 'application/json'})
         else:
             r = requests.post(sigurl, data=str_signal_data,
-                              headers={'content-type': None})
+                              headers={'content-type': 'application/json'})
         log.debug('Response %s ' % r)
 
     if 'deploy_queue_id' in iv:
diff --git a/tests/software_config/test_heat_config_notify.py b/tests/software_config/test_heat_config_notify.py
index 5aea988..c3d5d20 100644
--- a/tests/software_config/test_heat_config_notify.py
+++ b/tests/software_config/test_heat_config_notify.py
@@ -118,7 +118,7 @@ class HeatConfigNotifyTest(common.RunScriptTest):
         requests.post.assert_called_once_with(
             'mock://192.0.2.3/foo',
             data=signal_data,
-            headers={'content-type': None})
+            headers={'content-type': 'application/json'})
 
     def test_notify_signal_id_put(self):
         requests = mock.MagicMock()
@@ -136,7 +136,7 @@ class HeatConfigNotifyTest(common.RunScriptTest):
         requests.put.assert_called_once_with(
             'mock://192.0.2.3/foo',
             data=signal_data,
-            headers={'content-type': None})
+            headers={'content-type': 'application/json'})
 
     def test_notify_signal_id_empty_data(self):
         requests = mock.MagicMock()
@@ -153,7 +153,7 @@ class HeatConfigNotifyTest(common.RunScriptTest):
         requests.post.assert_called_once_with(
             'mock://192.0.2.3/foo',
             data='{}',
-            headers={'content-type': None})
+            headers={'content-type': 'application/json'})
 
     def test_notify_signal_id_invalid_json_data(self):
         requests = mock.MagicMock()
@@ -170,7 +170,7 @@ class HeatConfigNotifyTest(common.RunScriptTest):
         requests.post.assert_called_once_with(
             'mock://192.0.2.3/foo',
             data='{}',
-            headers={'content-type': None})
+            headers={'content-type': 'application/json'})
 
     def test_notify_heat_signal(self):
         ksclient = mock.MagicMock()