diff --git a/zerver/test_hooks.py b/zerver/test_hooks.py
index e9529dcd75..4d0b021d0b 100644
--- a/zerver/test_hooks.py
+++ b/zerver/test_hooks.py
@@ -796,6 +796,15 @@ class PagerDutyHookTests(AuthedTestCase):
             ':average_heart: Incident [1](https://zulip-test.pagerduty.com/incidents/PO1XIJ5) acknowledged by [armooo@](https://zulip-test.pagerduty.com/users/POBCFRJ)\n\n>It is on fire'
         )
 
+    def test_no_subject(self):
+        data = ujson.loads(self.fixture_data('pagerduty', 'mp_fail'))
+        msg = self.send_webhook(data, 'pagerduty')
+        self.assertEqual(msg.subject, 'incident 48219')
+        self.assertEqual(
+            msg.content,
+            ':healthy_heart: Incident [48219](https://dropbox.pagerduty.com/incidents/PJKGZF9) resolved\n\n>mp_error_block_down_critical'
+        )
+
     def test_bad_message(self):
         data = {'messages': [{'type': 'incident.triggered'}]}
         msg = self.send_webhook(data, 'pagerduty')
diff --git a/zerver/views/webhooks.py b/zerver/views/webhooks.py
index 0fbf431cd5..59b5002915 100644
--- a/zerver/views/webhooks.py
+++ b/zerver/views/webhooks.py
@@ -961,7 +961,14 @@ def build_pagerdudy_formatdict(message):
         format_dict['resolved_by_username'] = 'nobody'
         format_dict['resolved_by_url'] = ''
 
-    format_dict['trigger_subject'] = message['data']['incident']['trigger_summary_data']['subject']
+    trigger_message = []
+    trigger_subject = message['data']['incident']['trigger_summary_data'].get('subject', '')
+    if trigger_subject:
+        trigger_message.append(trigger_subject)
+    trigger_description = message['data']['incident']['trigger_summary_data'].get('description', '')
+    if trigger_description:
+        trigger_message.append(trigger_description)
+    format_dict['trigger_message'] = '\n'.join(trigger_message)
     return format_dict
 
 
@@ -981,18 +988,18 @@ def send_formated_pagerduty(user_profile, stream, message_type, format_dict):
         template = (':unhealthy_heart: Incident '
         '[{incident_num}]({incident_url}) {action} by '
         '[{service_name}]({service_url}) and assigned to '
-        '[{assigned_to_username}@]({assigned_to_url})\n\n>{trigger_subject}')
+        '[{assigned_to_username}@]({assigned_to_url})\n\n>{trigger_message}')
 
     elif message_type == 'incident.resolve' and format_dict['resolved_by_url']:
         template = (':healthy_heart: Incident '
         '[{incident_num}]({incident_url}) resolved by '
-        '[{resolved_by_username}@]({resolved_by_url})\n\n>{trigger_subject}')
+        '[{resolved_by_username}@]({resolved_by_url})\n\n>{trigger_message}')
     elif message_type == 'incident.resolve' and not format_dict['resolved_by_url']:
         template = (':healthy_heart: Incident '
-        '[{incident_num}]({incident_url}) resolved\n\n>{trigger_subject}')
+        '[{incident_num}]({incident_url}) resolved\n\n>{trigger_message}')
     else:
         template = (':average_heart: Incident [{incident_num}]({incident_url}) '
-        '{action} by [{assigned_to_username}@]({assigned_to_url})\n\n>{trigger_subject}')
+        '{action} by [{assigned_to_username}@]({assigned_to_url})\n\n>{trigger_message}')
 
     subject = 'incident {incident_num}'.format(**format_dict)
     body = template.format(**format_dict)