diff --git a/docs/api/differences_in_mastoapi_responses.md b/docs/api/differences_in_mastoapi_responses.md
index 197c465d8..f34e3dd72 100644
--- a/docs/api/differences_in_mastoapi_responses.md
+++ b/docs/api/differences_in_mastoapi_responses.md
@@ -25,7 +25,7 @@ Has these additional fields under the `pleroma` object:
 - `in_reply_to_account_acct`: the `acct` property of User entity for replied user (if any)
 - `content`: a map consisting of alternate representations of the `content` property with the key being it's mimetype. Currently the only alternate representation supported is `text/plain`
 - `spoiler_text`: a map consisting of alternate representations of the `spoiler_text` property with the key being it's mimetype. Currently the only alternate representation supported is `text/plain`
-- `expires_on`: a datetime (iso8601) that states when the post will expire (be deleted automatically), or empty if the post won't expire
+- `expires_at`: a datetime (iso8601) that states when the post will expire (be deleted automatically), or empty if the post won't expire
 
 ## Attachments
 
@@ -87,7 +87,7 @@ Additional parameters can be added to the JSON body/Form data:
 - `content_type`: string, contain the MIME type of the status, it is transformed into HTML by the backend. You can get the list of the supported MIME types with the nodeinfo endpoint.
 - `to`: A list of nicknames (like `lain@soykaf.club` or `lain` on the local server) that will be used to determine who is going to be addressed by this post. Using this will disable the implicit addressing by mentioned names in the `status` body, only the people in the `to` list will be addressed. The normal rules for for post visibility are not affected by this and will still apply.
 - `visibility`: string, besides standard MastoAPI values (`direct`, `private`, `unlisted` or `public`) it can be used to address a List by setting it to `list:LIST_ID`.
-- `expires_on`: datetime (iso8601), sets when the posted activity should expire. When a posted activity expires it will be deleted from the server, and a delete request for it will be federated.
+- `expires_in`: The number of seconds the posted activity should expire in. When a posted activity expires it will be deleted from the server, and a delete request for it will be federated. This needs to be longer than an hour.
 - `in_reply_to_conversation_id`: Will reply to a given conversation, addressing only the people who are part of the recipient set of that conversation. Sets the visibility to `direct`.
 
 ## PATCH `/api/v1/update_credentials`