diff --git a/zerver/lib/slack_data_to_zulip_data.py b/zerver/lib/slack_data_to_zulip_data.py
index 53452fd1a9..918c9057ec 100755
--- a/zerver/lib/slack_data_to_zulip_data.py
+++ b/zerver/lib/slack_data_to_zulip_data.py
@@ -586,7 +586,7 @@ def channel_message_to_zerver_message(realm_id: int, users: List[ZerverFieldsT],
             sending_client=1,
             rendered_content_version=1,  # This is Zulip-specific
             has_image=message.get('has_image', False),
-            subject='from slack',  # This is Zulip-specific
+            subject='imported from slack',  # This is Zulip-specific
             pub_date=float(message['ts']),
             id=message_id,
             has_attachment=has_attachment,  # attachment will be posted in the subsequent message;
diff --git a/zerver/tests/test_slack_importer.py b/zerver/tests/test_slack_importer.py
index 1309b154d4..4fe84d350d 100644
--- a/zerver/tests/test_slack_importer.py
+++ b/zerver/tests/test_slack_importer.py
@@ -448,9 +448,9 @@ class SlackImporter(ZulipTestCase):
         self.assertEqual(zerver_message[2]['content'], 'http://journals.plos.org/plosone/article')
         self.assertEqual(zerver_message[2]['has_link'], True)
 
-        self.assertEqual(zerver_message[3]['subject'], 'from slack')
+        self.assertEqual(zerver_message[3]['subject'], 'imported from slack')
         self.assertEqual(zerver_message[4]['recipient'], added_recipient['general'])
-        self.assertEqual(zerver_message[2]['subject'], 'from slack')
+        self.assertEqual(zerver_message[2]['subject'], 'imported from slack')
         self.assertEqual(zerver_message[1]['recipient'], added_recipient['random'])
 
         self.assertEqual(zerver_message[1]['id'], 4)