diff --git a/awx/main/notifications/slack_backend.py b/awx/main/notifications/slack_backend.py
index 983fb73cf5..24b7876708 100644
--- a/awx/main/notifications/slack_backend.py
+++ b/awx/main/notifications/slack_backend.py
@@ -55,7 +55,7 @@ class SlackBackend(AWXBaseEmailBackend):
                     if ret['ok']:
                         sent_messages += 1
                     else:
-                        raise RuntimeError("Slack Notification unable to send {}: {}".format(r, m.subject))
+                        raise RuntimeError("Slack Notification unable to send {}: {} ({})".format(r, m.subject, ret['error']))
             except Exception as e:
                 logger.error(smart_text(_("Exception sending messages: {}").format(e)))
                 if not self.fail_silently: