diff --git a/awx/main/management/commands/run_task_system.py b/awx/main/management/commands/run_task_system.py
index 40eccaf1b3..067a878d82 100644
--- a/awx/main/management/commands/run_task_system.py
+++ b/awx/main/management/commands/run_task_system.py
@@ -242,7 +242,9 @@ def process_graph(graph, task_capacity):
             start_status = node_obj.start(error_callback=error_handler)
             if not start_status:
                 node_obj.status = 'failed'
-                node_obj.job_explanation += "Task failed pre-start check"
+                if node_obj.job_explanation:
+                    node_obj.job_explanation += ' '
+                node_obj.job_explanation += 'Task failed pre-start check.'
                 node_obj.save()
                 # TODO: Run error handler
                 continue
diff --git a/awx/main/models/unified_jobs.py b/awx/main/models/unified_jobs.py
index 2a0898facb..9e18ccf361 100644
--- a/awx/main/models/unified_jobs.py
+++ b/awx/main/models/unified_jobs.py
@@ -572,7 +572,7 @@ class UnifiedJob(PolymorphicModel, PasswordFieldsModel, CommonModelNameNotUnique
         opts = dict([(field, start_args.get(field, '')) for field in needed])
         if not all(opts.values()):
             missing_fields = ', '.join([k for k,v in opts.items() if not v])
-            self.job_explanation = u'Missing needed fields: %s' % missing_fields
+            self.job_explanation = u'Missing needed fields: %s.' % missing_fields
             self.save(update_fields=['job_explanation'])
             return False
         task_class().apply_async((self.pk,), opts, link_error=error_callback)