diff --git a/docs/API/chats.md b/docs/API/chats.md
index 1ea18ff5f..2e415e4da 100644
--- a/docs/API/chats.md
+++ b/docs/API/chats.md
@@ -68,7 +68,8 @@ Returned data:
   },
   "id" : "1",
   "unread" : 2,
-  "last_message" : {...} // The last message in that chat
+  "last_message" : {...}, // The last message in that chat
+  "updated_at": "2020-04-21T15:11:46.000Z"
 }
 ```
 
@@ -88,7 +89,8 @@ Returned data:
     ...
   },
   "id" : "1",
-  "unread" : 0
+  "unread" : 0,
+  "updated_at": "2020-04-21T15:11:46.000Z"
 }
 ```
 
@@ -112,7 +114,8 @@ Returned data:
       },
       "id" : "1",
       "unread" : 2,
-      "last_message" : {...} // The last message in that chat
+      "last_message" : {...}, // The last message in that chat
+      "updated_at": "2020-04-21T15:11:46.000Z"
    }
 ]
 ```
diff --git a/lib/pleroma/web/api_spec/schemas/chat.ex b/lib/pleroma/web/api_spec/schemas/chat.ex
index c6ec07c88..b4986b734 100644
--- a/lib/pleroma/web/api_spec/schemas/chat.ex
+++ b/lib/pleroma/web/api_spec/schemas/chat.ex
@@ -16,7 +16,8 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Chat do
       id: %Schema{type: :string},
       account: %Schema{type: :object},
       unread: %Schema{type: :integer},
-      last_message: ChatMessage
+      last_message: ChatMessage,
+      updated_at: %Schema{type: :string, format: :"date-time"}
     },
     example: %{
       "account" => %{
@@ -67,7 +68,8 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Chat do
       },
       "id" => "1",
       "unread" => 2,
-      "last_message" => ChatMessage.schema().example()
+      "last_message" => ChatMessage.schema().example(),
+      "updated_at" => "2020-04-21T15:06:45.000Z"
     }
   })
 end