diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90d10fdbc..336aa937f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -68,6 +68,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Mastodon API: Add `pleroma.deactivated` to the Account entity
 - Mastodon API: added `/auth/password` endpoint for password reset with rate limit.
 - Mastodon API: /api/v1/accounts/:id/statuses now supports nicknames or user id
+- Mastodon API: Improve support for the user profile custom fields
 - Admin API: Return users' tags when querying reports
 - Admin API: Return avatar and display name when querying users
 - Admin API: Allow querying user by ID
diff --git a/config/config.exs b/config/config.exs
index 758661120..7279b43b7 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -255,6 +255,10 @@
   dynamic_configuration: false,
   user_bio_length: 5000,
   user_name_length: 100,
+  max_account_fields: 10,
+  max_remote_account_fields: 20,
+  account_field_name_length: 255,
+  account_field_value_length: 255,
   external_user_synchronization: true
 
 config :pleroma, :markup,
diff --git a/docs/config.md b/docs/config.md
index 20311db54..7e4e96db0 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -132,6 +132,10 @@ config :pleroma, Pleroma.Emails.Mailer,
 * `skip_thread_containment`: Skip filter out broken threads. The default is `false`.
 * `limit_to_local_content`: Limit unauthenticated users to search for local statutes and users only. Possible values: `:unauthenticated`, `:all` and `false`. The default is `:unauthenticated`.
 * `dynamic_configuration`: Allow transferring configuration to DB with the subsequent customization from Admin api.
+* `max_account_fields`: The maximum number of custom fields in the user profile (default: `10`)
+* `max_remote_account_fields`: The maximum number of custom fields in the remote user profile (default: `20`)
+* `account_field_name_length`: An account field name maximum length (default: `255`)
+* `account_field_value_length`: An account field value maximum length (default: `255`)
 * `external_user_synchronization`: Enabling following/followers counters synchronization for external users.
 
 
diff --git a/lib/pleroma/html.ex b/lib/pleroma/html.ex
index 06e60cba3..3951f0f51 100644
--- a/lib/pleroma/html.ex
+++ b/lib/pleroma/html.ex
@@ -282,3 +282,31 @@ def scrub({tag, attributes, children}), do: {tag, attributes, children}
   def scrub({_tag, children}), do: children
   def scrub(text), do: text
 end
+
+defmodule Pleroma.HTML.Scrubber.LinksOnly do
+  @moduledoc """
+  An HTML scrubbing policy which limits to links only.
+  """
+
+  @valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
+
+  require HtmlSanitizeEx.Scrubber.Meta
+  alias HtmlSanitizeEx.Scrubber.Meta
+
+  Meta.remove_cdata_sections_before_scrub()
+  Meta.strip_comments()
+
+  # links
+  Meta.allow_tag_with_uri_attributes("a", ["href"], @valid_schemes)
+
+  Meta.allow_tag_with_this_attribute_values("a", "rel", [
+    "tag",
+    "nofollow",
+    "noopener",
+    "noreferrer",
+    "me"
+  ])
+
+  Meta.allow_tag_with_these_attributes("a", ["name", "title"])
+  Meta.strip_everything_not_covered()
+end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 02011f4e6..134b8bb6c 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -222,12 +222,12 @@ def update_changeset(struct, params \\ %{}) do
     |> validate_length(:name, min: 1, max: name_limit)
   end
 
-  def upgrade_changeset(struct, params \\ %{}) do
+  def upgrade_changeset(struct, params \\ %{}, remote? \\ false) do
     bio_limit = Pleroma.Config.get([:instance, :user_bio_length], 5000)
     name_limit = Pleroma.Config.get([:instance, :user_name_length], 100)
 
     params = Map.put(params, :last_refreshed_at, NaiveDateTime.utc_now())
-    info_cng = User.Info.user_upgrade(struct.info, params[:info])
+    info_cng = User.Info.user_upgrade(struct.info, params[:info], remote?)
 
     struct
     |> cast(params, [
diff --git a/lib/pleroma/user/info.ex b/lib/pleroma/user/info.ex
index 22eb9a182..45a39924b 100644
--- a/lib/pleroma/user/info.ex
+++ b/lib/pleroma/user/info.ex
@@ -49,6 +49,8 @@ defmodule Pleroma.User.Info do
     field(:mascot, :map, default: nil)
     field(:emoji, {:array, :map}, default: [])
     field(:pleroma_settings_store, :map, default: %{})
+    field(:fields, {:array, :map}, default: [])
+    field(:raw_fields, {:array, :map}, default: [])
 
     field(:notification_settings, :map,
       default: %{
@@ -254,11 +256,13 @@ def remote_user_creation(info, params) do
       :hide_followers,
       :hide_follows,
       :follower_count,
+      :fields,
       :following_count
     ])
+    |> validate_fields(true)
   end
 
-  def user_upgrade(info, params) do
+  def user_upgrade(info, params, remote? \\ false) do
     info
     |> cast(params, [
       :ap_enabled,
@@ -269,8 +273,10 @@ def user_upgrade(info, params) do
       :follower_count,
       :following_count,
       :hide_follows,
+      :fields,
       :hide_followers
     ])
+    |> validate_fields(remote?)
   end
 
   def profile_update(info, params) do
@@ -286,10 +292,40 @@ def profile_update(info, params) do
       :background,
       :show_role,
       :skip_thread_containment,
+      :fields,
+      :raw_fields,
       :pleroma_settings_store
     ])
+    |> validate_fields()
   end
 
+  def validate_fields(changeset, remote? \\ false) do
+    limit_name = if remote?, do: :max_remote_account_fields, else: :max_account_fields
+    limit = Pleroma.Config.get([:instance, limit_name], 0)
+
+    changeset
+    |> validate_length(:fields, max: limit)
+    |> validate_change(:fields, fn :fields, fields ->
+      if Enum.all?(fields, &valid_field?/1) do
+        []
+      else
+        [fields: "invalid"]
+      end
+    end)
+  end
+
+  defp valid_field?(%{"name" => name, "value" => value}) do
+    name_limit = Pleroma.Config.get([:instance, :account_field_name_length], 255)
+    value_limit = Pleroma.Config.get([:instance, :account_field_value_length], 255)
+
+    is_binary(name) &&
+      is_binary(value) &&
+      String.length(name) <= name_limit &&
+      String.length(value) <= value_limit
+  end
+
+  defp valid_field?(_), do: false
+
   @spec confirmation_changeset(Info.t(), keyword()) :: Changeset.t()
   def confirmation_changeset(info, opts) do
     need_confirmation? = Keyword.get(opts, :need_confirmation)
@@ -384,6 +420,19 @@ def remove_reblog_mute(info, ap_id) do
     cast(info, params, [:muted_reblogs])
   end
 
+  # ``fields`` is an array of mastodon profile field, containing ``{"name": "…", "value": "…"}``.
+  # For example: [{"name": "Pronoun", "value": "she/her"}, …]
+  def fields(%{fields: [], source_data: %{"attachment" => attachment}}) do
+    limit = Pleroma.Config.get([:instance, :max_remote_account_fields], 0)
+
+    attachment
+    |> Enum.filter(fn %{"type" => t} -> t == "PropertyValue" end)
+    |> Enum.map(fn fields -> Map.take(fields, ["name", "value"]) end)
+    |> Enum.take(limit)
+  end
+
+  def fields(%{fields: fields}), do: fields
+
   def follow_information_update(info, params) do
     info
     |> cast(params, [
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 1a8e3ad96..af9749d13 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -1023,6 +1023,12 @@ defp object_to_user_data(data) do
           "url" => [%{"href" => data["image"]["url"]}]
         }
 
+    fields =
+      data
+      |> Map.get("attachment", [])
+      |> Enum.filter(fn %{"type" => t} -> t == "PropertyValue" end)
+      |> Enum.map(fn fields -> Map.take(fields, ["name", "value"]) end)
+
     locked = data["manuallyApprovesFollowers"] || false
     data = Transmogrifier.maybe_fix_user_object(data)
 
@@ -1032,6 +1038,7 @@ defp object_to_user_data(data) do
         ap_enabled: true,
         source_data: data,
         banner: banner,
+        fields: fields,
         locked: locked
       },
       avatar: avatar,
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 0fcc81bf3..36340a3a1 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -598,14 +598,20 @@ def handle_incoming(
 
       banner = new_user_data[:info][:banner]
       locked = new_user_data[:info][:locked] || false
+      attachment = get_in(new_user_data, [:info, :source_data, "attachment"]) || []
+
+      fields =
+        attachment
+        |> Enum.filter(fn %{"type" => t} -> t == "PropertyValue" end)
+        |> Enum.map(fn fields -> Map.take(fields, ["name", "value"]) end)
 
       update_data =
         new_user_data
         |> Map.take([:name, :bio, :avatar])
-        |> Map.put(:info, %{banner: banner, locked: locked})
+        |> Map.put(:info, %{banner: banner, locked: locked, fields: fields})
 
       actor
-      |> User.upgrade_changeset(update_data)
+      |> User.upgrade_changeset(update_data, true)
       |> User.update_and_set_cache()
 
       ActivityPub.update(%{
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index 06c9e1c71..7be734b26 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -80,6 +80,17 @@ def render("user.json", %{user: user}) do
       |> Transmogrifier.add_emoji_tags()
       |> Map.get("tag", [])
 
+    fields =
+      user.info
+      |> User.Info.fields()
+      |> Enum.map(fn %{"name" => name, "value" => value} ->
+        %{
+          "name" => Pleroma.HTML.strip_tags(name),
+          "value" => Pleroma.HTML.filter_tags(value, Pleroma.HTML.Scrubber.LinksOnly)
+        }
+      end)
+      |> Enum.map(&Map.put(&1, "type", "PropertyValue"))
+
     %{
       "id" => user.ap_id,
       "type" => "Person",
@@ -98,6 +109,7 @@ def render("user.json", %{user: user}) do
         "publicKeyPem" => public_key
       },
       "endpoints" => endpoints,
+      "attachment" => fields,
       "tag" => (user.info.source_data["tag"] || []) ++ user_tags
     }
     |> Map.merge(maybe_make_image(&User.avatar_url/2, "icon", user))
diff --git a/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex b/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
index 8fe7be8be..53cf95fbb 100644
--- a/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
+++ b/lib/pleroma/web/mastodon_api/mastodon_api_controller.ex
@@ -138,7 +138,9 @@ def update_credentials(%{assigns: %{user: user}} = conn, params) do
     emojis_text = (user_params["display_name"] || "") <> (user_params["note"] || "")
 
     user_info_emojis =
-      ((user.info.emoji || []) ++ Formatter.get_emoji_map(emojis_text))
+      user.info
+      |> Map.get(:emoji, [])
+      |> Enum.concat(Formatter.get_emoji_map(emojis_text))
       |> Enum.dedup()
 
     info_params =
@@ -157,6 +159,12 @@ def update_credentials(%{assigns: %{user: user}} = conn, params) do
         end)
       end)
       |> add_if_present(params, "default_scope", :default_scope)
+      |> add_if_present(params, "fields", :fields, fn fields ->
+        fields = Enum.map(fields, fn f -> Map.update!(f, "value", &AutoLinker.link(&1)) end)
+
+        {:ok, fields}
+      end)
+      |> add_if_present(params, "fields", :raw_fields)
       |> add_if_present(params, "pleroma_settings_store", :pleroma_settings_store, fn value ->
         {:ok, Map.merge(user.info.pleroma_settings_store, value)}
       end)
diff --git a/lib/pleroma/web/mastodon_api/views/account_view.ex b/lib/pleroma/web/mastodon_api/views/account_view.ex
index 0ef568f0f..169116d0d 100644
--- a/lib/pleroma/web/mastodon_api/views/account_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/account_view.ex
@@ -94,12 +94,18 @@ defp do_render("account.json", %{user: user} = opts) do
       end)
 
     fields =
-      (user.info.source_data["attachment"] || [])
-      |> Enum.filter(fn %{"type" => t} -> t == "PropertyValue" end)
-      |> Enum.map(fn fields -> Map.take(fields, ["name", "value"]) end)
+      user.info
+      |> User.Info.fields()
+      |> Enum.map(fn %{"name" => name, "value" => value} ->
+        %{
+          "name" => Pleroma.HTML.strip_tags(name),
+          "value" => Pleroma.HTML.filter_tags(value, Pleroma.HTML.Scrubber.LinksOnly)
+        }
+      end)
+
+    raw_fields = Map.get(user.info, :raw_fields, [])
 
     bio = HTML.filter_tags(user.bio, User.html_filter_policy(opts[:for]))
-
     relationship = render("relationship.json", %{user: opts[:for], target: user})
 
     %{
@@ -124,6 +130,7 @@ defp do_render("account.json", %{user: user} = opts) do
       source: %{
         note: HTML.strip_tags((user.bio || "") |> String.replace("<br>", "\n")),
         sensitive: false,
+        fields: raw_fields,
         pleroma: %{}
       },
 
diff --git a/lib/pleroma/web/twitter_api/views/user_view.ex b/lib/pleroma/web/twitter_api/views/user_view.ex
index 8d8892068..8a7d2fc72 100644
--- a/lib/pleroma/web/twitter_api/views/user_view.ex
+++ b/lib/pleroma/web/twitter_api/views/user_view.ex
@@ -74,12 +74,15 @@ defp do_render("user.json", %{user: user = %User{}} = assigns) do
       |> HTML.filter_tags(User.html_filter_policy(for_user))
       |> Formatter.emojify(emoji)
 
-    # ``fields`` is an array of mastodon profile field, containing ``{"name": "…", "value": "…"}``.
-    # For example: [{"name": "Pronoun", "value": "she/her"}, …]
     fields =
-      (user.info.source_data["attachment"] || [])
-      |> Enum.filter(fn %{"type" => t} -> t == "PropertyValue" end)
-      |> Enum.map(fn fields -> Map.take(fields, ["name", "value"]) end)
+      user.info
+      |> User.Info.fields()
+      |> Enum.map(fn %{"name" => name, "value" => value} ->
+        %{
+          "name" => Pleroma.HTML.strip_tags(name),
+          "value" => Pleroma.HTML.filter_tags(value, Pleroma.HTML.Scrubber.LinksOnly)
+        }
+      end)
 
     data =
       %{
diff --git a/test/fixtures/mastodon-update.json b/test/fixtures/mastodon-update.json
index f6713fea5..dbf8b6dff 100644
--- a/test/fixtures/mastodon-update.json
+++ b/test/fixtures/mastodon-update.json
@@ -1,10 +1,10 @@
-{                                                                               
-  "type": "Update",                                                                    
-  "object": {                                                                          
-    "url": "http://mastodon.example.org/@gargron",                                     
-    "type": "Person",                                                                  
-    "summary": "<p>Some bio</p>",                                                              
-    "publicKey": {                                                                     
+{
+  "type": "Update",
+  "object": {
+    "url": "http://mastodon.example.org/@gargron",
+    "type": "Person",
+    "summary": "<p>Some bio</p>",
+    "publicKey": {
       "publicKeyPem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0gs3VnQf6am3R+CeBV4H\nlfI1HZTNRIBHgvFszRZkCERbRgEWMu+P+I6/7GJC5H5jhVQ60z4MmXcyHOGmYMK/\n5XyuHQz7V2Ssu1AxLfRN5Biq1ayb0+DT/E7QxNXDJPqSTnstZ6C7zKH/uAETqg3l\nBonjCQWyds+IYbQYxf5Sp3yhvQ80lMwHML3DaNCMlXWLoOnrOX5/yK5+dedesg2\n/HIvGk+HEt36vm6hoH7bwPuEkgA++ACqwjXRe5Mta7i3eilHxFaF8XIrJFARV0t\nqOu4GID/jG6oA+swIWndGrtR2QRJIt9QIBFfK3HG5M0koZbY1eTqwNFRHFL3xaD\nUQIDAQAB\n-----END PUBLIC KEY-----\n",
       "owner": "http://mastodon.example.org/users/gargron",
       "id": "http://mastodon.example.org/users/gargron#main-key"
@@ -20,7 +20,27 @@
     "endpoints": {
       "sharedInbox": "http://mastodon.example.org/inbox"
     },
-    "icon":{"type":"Image","mediaType":"image/jpeg","url":"https://cd.niu.moe/accounts/avatars/000/033/323/original/fd7f8ae0b3ffedc9.jpeg"},"image":{"type":"Image","mediaType":"image/png","url":"https://cd.niu.moe/accounts/headers/000/033/323/original/850b3448fa5fd477.png"}
+    "attachment": [{
+        "type": "PropertyValue",
+        "name": "foo",
+        "value": "updated"
+      },
+      {
+        "type": "PropertyValue",
+        "name": "foo1",
+        "value": "updated"
+      }
+    ],
+    "icon": {
+      "type": "Image",
+      "mediaType": "image/jpeg",
+      "url": "https://cd.niu.moe/accounts/avatars/000/033/323/original/fd7f8ae0b3ffedc9.jpeg"
+    },
+    "image": {
+      "type": "Image",
+      "mediaType": "image/png",
+      "url": "https://cd.niu.moe/accounts/headers/000/033/323/original/850b3448fa5fd477.png"
+    }
   },
   "id": "http://mastodon.example.org/users/gargron#updates/1519563538",
   "actor": "http://mastodon.example.org/users/gargron",
diff --git a/test/fixtures/tesla_mock/admin@mastdon.example.org.json b/test/fixtures/tesla_mock/admin@mastdon.example.org.json
index c297e4349..8159dc20a 100644
--- a/test/fixtures/tesla_mock/admin@mastdon.example.org.json
+++ b/test/fixtures/tesla_mock/admin@mastdon.example.org.json
@@ -1 +1,54 @@
-{"@context":["https://www.w3.org/ns/activitystreams","https://w3id.org/security/v1",{"manuallyApprovesFollowers":"as:manuallyApprovesFollowers","sensitive":"as:sensitive","movedTo":"as:movedTo","Hashtag":"as:Hashtag","ostatus":"http://ostatus.org#","atomUri":"ostatus:atomUri","inReplyToAtomUri":"ostatus:inReplyToAtomUri","conversation":"ostatus:conversation","toot":"http://joinmastodon.org/ns#","Emoji":"toot:Emoji"}],"id":"http://mastodon.example.org/users/admin","type":"Person","following":"http://mastodon.example.org/users/admin/following","followers":"http://mastodon.example.org/users/admin/followers","inbox":"http://mastodon.example.org/users/admin/inbox","outbox":"http://mastodon.example.org/users/admin/outbox","preferredUsername":"admin","name":null,"summary":"\u003cp\u003e\u003c/p\u003e","url":"http://mastodon.example.org/@admin","manuallyApprovesFollowers":false,"publicKey":{"id":"http://mastodon.example.org/users/admin#main-key","owner":"http://mastodon.example.org/users/admin","publicKeyPem":"-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtc4Tir+3ADhSNF6VKrtW\nOU32T01w7V0yshmQei38YyiVwVvFu8XOP6ACchkdxbJ+C9mZud8qWaRJKVbFTMUG\nNX4+6Q+FobyuKrwN7CEwhDALZtaN2IPbaPd6uG1B7QhWorrY+yFa8f2TBM3BxnUy\nI4T+bMIZIEYG7KtljCBoQXuTQmGtuffO0UwJksidg2ffCF5Q+K//JfQagJ3UzrR+\nZXbKMJdAw4bCVJYs4Z5EhHYBwQWiXCyMGTd7BGlmMkY6Av7ZqHKC/owp3/0EWDNz\nNqF09Wcpr3y3e8nA10X40MJqp/wR+1xtxp+YGbq/Cj5hZGBG7etFOmIpVBrDOhry\nBwIDAQAB\n-----END PUBLIC KEY-----\n"},"endpoints":{"sharedInbox":"http://mastodon.example.org/inbox"},"icon":{"type":"Image","mediaType":"image/jpeg","url":"https://cdn.niu.moe/accounts/avatars/000/033/323/original/fd7f8ae0b3ffedc9.jpeg"},"image":{"type":"Image","mediaType":"image/png","url":"https://cdn.niu.moe/accounts/headers/000/033/323/original/850b3448fa5fd477.png"}}
+{
+  "@context": ["https://www.w3.org/ns/activitystreams", "https://w3id.org/security/v1", {
+    "manuallyApprovesFollowers": "as:manuallyApprovesFollowers",
+    "sensitive": "as:sensitive",
+    "movedTo": "as:movedTo",
+    "Hashtag": "as:Hashtag",
+    "ostatus": "http://ostatus.org#",
+    "atomUri": "ostatus:atomUri",
+    "inReplyToAtomUri": "ostatus:inReplyToAtomUri",
+    "conversation": "ostatus:conversation",
+    "toot": "http://joinmastodon.org/ns#",
+    "Emoji": "toot:Emoji"
+  }],
+  "id": "http://mastodon.example.org/users/admin",
+  "type": "Person",
+  "following": "http://mastodon.example.org/users/admin/following",
+  "followers": "http://mastodon.example.org/users/admin/followers",
+  "inbox": "http://mastodon.example.org/users/admin/inbox",
+  "outbox": "http://mastodon.example.org/users/admin/outbox",
+  "preferredUsername": "admin",
+  "name": null,
+  "summary": "\u003cp\u003e\u003c/p\u003e",
+  "url": "http://mastodon.example.org/@admin",
+  "manuallyApprovesFollowers": false,
+  "publicKey": {
+    "id": "http://mastodon.example.org/users/admin#main-key",
+    "owner": "http://mastodon.example.org/users/admin",
+    "publicKeyPem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtc4Tir+3ADhSNF6VKrtW\nOU32T01w7V0yshmQei38YyiVwVvFu8XOP6ACchkdxbJ+C9mZud8qWaRJKVbFTMUG\nNX4+6Q+FobyuKrwN7CEwhDALZtaN2IPbaPd6uG1B7QhWorrY+yFa8f2TBM3BxnUy\nI4T+bMIZIEYG7KtljCBoQXuTQmGtuffO0UwJksidg2ffCF5Q+K//JfQagJ3UzrR+\nZXbKMJdAw4bCVJYs4Z5EhHYBwQWiXCyMGTd7BGlmMkY6Av7ZqHKC/owp3/0EWDNz\nNqF09Wcpr3y3e8nA10X40MJqp/wR+1xtxp+YGbq/Cj5hZGBG7etFOmIpVBrDOhry\nBwIDAQAB\n-----END PUBLIC KEY-----\n"
+  },
+  "attachment": [{
+      "type": "PropertyValue",
+      "name": "foo",
+      "value": "bar"
+    },
+    {
+      "type": "PropertyValue",
+      "name": "foo1",
+      "value": "bar1"
+    }
+  ],
+  "endpoints": {
+    "sharedInbox": "http://mastodon.example.org/inbox"
+  },
+  "icon": {
+    "type": "Image",
+    "mediaType": "image/jpeg",
+    "url": "https://cdn.niu.moe/accounts/avatars/000/033/323/original/fd7f8ae0b3ffedc9.jpeg"
+  },
+  "image": {
+    "type": "Image",
+    "mediaType": "image/png",
+    "url": "https://cdn.niu.moe/accounts/headers/000/033/323/original/850b3448fa5fd477.png"
+  }
+}
diff --git a/test/web/activity_pub/transmogrifier_test.exs b/test/web/activity_pub/transmogrifier_test.exs
index 060b91e29..d8fbcd628 100644
--- a/test/web/activity_pub/transmogrifier_test.exs
+++ b/test/web/activity_pub/transmogrifier_test.exs
@@ -509,6 +509,60 @@ test "it works for incoming update activities" do
       assert user.bio == "<p>Some bio</p>"
     end
 
+    test "it works with custom profile fields" do
+      {:ok, activity} =
+        "test/fixtures/mastodon-post-activity.json"
+        |> File.read!()
+        |> Poison.decode!()
+        |> Transmogrifier.handle_incoming()
+
+      user = User.get_cached_by_ap_id(activity.actor)
+
+      assert User.Info.fields(user.info) == [
+               %{"name" => "foo", "value" => "bar"},
+               %{"name" => "foo1", "value" => "bar1"}
+             ]
+
+      update_data = File.read!("test/fixtures/mastodon-update.json") |> Poison.decode!()
+
+      object =
+        update_data["object"]
+        |> Map.put("actor", user.ap_id)
+        |> Map.put("id", user.ap_id)
+
+      update_data =
+        update_data
+        |> Map.put("actor", user.ap_id)
+        |> Map.put("object", object)
+
+      {:ok, _update_activity} = Transmogrifier.handle_incoming(update_data)
+
+      user = User.get_cached_by_ap_id(user.ap_id)
+
+      assert User.Info.fields(user.info) == [
+               %{"name" => "foo", "value" => "updated"},
+               %{"name" => "foo1", "value" => "updated"}
+             ]
+
+      Pleroma.Config.put([:instance, :max_remote_account_fields], 2)
+
+      update_data =
+        put_in(update_data, ["object", "attachment"], [
+          %{"name" => "foo", "type" => "PropertyValue", "value" => "bar"},
+          %{"name" => "foo11", "type" => "PropertyValue", "value" => "bar11"},
+          %{"name" => "foo22", "type" => "PropertyValue", "value" => "bar22"}
+        ])
+
+      {:ok, _} = Transmogrifier.handle_incoming(update_data)
+
+      user = User.get_cached_by_ap_id(user.ap_id)
+
+      assert User.Info.fields(user.info) == [
+               %{"name" => "foo", "value" => "updated"},
+               %{"name" => "foo1", "value" => "updated"}
+             ]
+    end
+
     test "it works for incoming update activities which lock the account" do
       data = File.read!("test/fixtures/mastodon-post-activity.json") |> Poison.decode!()
 
diff --git a/test/web/activity_pub/views/user_view_test.exs b/test/web/activity_pub/views/user_view_test.exs
index 86254117f..fb7fd9e79 100644
--- a/test/web/activity_pub/views/user_view_test.exs
+++ b/test/web/activity_pub/views/user_view_test.exs
@@ -22,6 +22,21 @@ test "Renders a user, including the public key" do
     assert String.contains?(result["publicKey"]["publicKeyPem"], "BEGIN PUBLIC KEY")
   end
 
+  test "Renders profile fields" do
+    fields = [
+      %{"name" => "foo", "value" => "bar"}
+    ]
+
+    {:ok, user} =
+      insert(:user)
+      |> User.upgrade_changeset(%{info: %{fields: fields}})
+      |> User.update_and_set_cache()
+
+    assert %{
+             "attachment" => [%{"name" => "foo", "type" => "PropertyValue", "value" => "bar"}]
+           } = UserView.render("user.json", %{user: user})
+  end
+
   test "Does not add an avatar image if the user hasn't set one" do
     user = insert(:user)
     {:ok, user} = User.ensure_keys_present(user)
diff --git a/test/web/mastodon_api/account_view_test.exs b/test/web/mastodon_api/account_view_test.exs
index a26f514a5..1d8b28339 100644
--- a/test/web/mastodon_api/account_view_test.exs
+++ b/test/web/mastodon_api/account_view_test.exs
@@ -67,7 +67,8 @@ test "Represent a user account" do
       source: %{
         note: "valid html",
         sensitive: false,
-        pleroma: %{}
+        pleroma: %{},
+        fields: []
       },
       pleroma: %{
         background_image: "https://example.com/images/asuka_hospital.png",
@@ -134,7 +135,8 @@ test "Represent a Service(bot) account" do
       source: %{
         note: user.bio,
         sensitive: false,
-        pleroma: %{}
+        pleroma: %{},
+        fields: []
       },
       pleroma: %{
         background_image: nil,
@@ -304,7 +306,8 @@ test "represent an embedded relationship" do
       source: %{
         note: user.bio,
         sensitive: false,
-        pleroma: %{}
+        pleroma: %{},
+        fields: []
       },
       pleroma: %{
         background_image: nil,
diff --git a/test/web/mastodon_api/mastodon_api_controller/update_credentials_test.exs b/test/web/mastodon_api/mastodon_api_controller/update_credentials_test.exs
index 71d0c8af8..dd443495b 100644
--- a/test/web/mastodon_api/mastodon_api_controller/update_credentials_test.exs
+++ b/test/web/mastodon_api/mastodon_api_controller/update_credentials_test.exs
@@ -300,5 +300,69 @@ test "updates profile emojos", %{conn: conn} do
       assert user["display_name"] == name
       assert [%{"shortcode" => "blank"}, %{"shortcode" => "firefox"}] = user["emojis"]
     end
+
+    test "update fields", %{conn: conn} do
+      user = insert(:user)
+
+      fields = [
+        %{"name" => "<a href=\"http://google.com\">foo</a>", "value" => "<script>bar</script>"},
+        %{"name" => "link", "value" => "cofe.io"}
+      ]
+
+      account =
+        conn
+        |> assign(:user, user)
+        |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+        |> json_response(200)
+
+      assert account["fields"] == [
+               %{"name" => "foo", "value" => "bar"},
+               %{"name" => "link", "value" => "<a href=\"http://cofe.io\">cofe.io</a>"}
+             ]
+
+      assert account["source"]["fields"] == [
+               %{
+                 "name" => "<a href=\"http://google.com\">foo</a>",
+                 "value" => "<script>bar</script>"
+               },
+               %{"name" => "link", "value" => "cofe.io"}
+             ]
+
+      name_limit = Pleroma.Config.get([:instance, :account_field_name_length])
+      value_limit = Pleroma.Config.get([:instance, :account_field_value_length])
+
+      long_value = Enum.map(0..value_limit, fn _ -> "x" end) |> Enum.join()
+
+      fields = [%{"name" => "<b>foo<b>", "value" => long_value}]
+
+      assert %{"error" => "Invalid request"} ==
+               conn
+               |> assign(:user, user)
+               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> json_response(403)
+
+      long_name = Enum.map(0..name_limit, fn _ -> "x" end) |> Enum.join()
+
+      fields = [%{"name" => long_name, "value" => "bar"}]
+
+      assert %{"error" => "Invalid request"} ==
+               conn
+               |> assign(:user, user)
+               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> json_response(403)
+
+      Pleroma.Config.put([:instance, :max_account_fields], 1)
+
+      fields = [
+        %{"name" => "<b>foo<b>", "value" => "<i>bar</i>"},
+        %{"name" => "link", "value" => "cofe.io"}
+      ]
+
+      assert %{"error" => "Invalid request"} ==
+               conn
+               |> assign(:user, user)
+               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> json_response(403)
+    end
   end
 end