diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ab4f7211..43f2935d9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [1.0.91] - 2019-??-??
 ### Added
 - Reverse Proxy: Do not retry failed requests to limit pressure on the peer
+- Mastodon API: Add support for `fields_attributes` API parameter (setting custom fields)
 
 ### Fixed
 - Mastodon API: Inability to get some local users by nickname in `/api/v1/accounts/:id_or_nickname`
diff --git a/lib/pleroma/web/mastodon_api/controllers/mastodon_api_controller.ex b/lib/pleroma/web/mastodon_api/controllers/mastodon_api_controller.ex
index edc5e7214..fcca6858d 100644
--- a/lib/pleroma/web/mastodon_api/controllers/mastodon_api_controller.ex
+++ b/lib/pleroma/web/mastodon_api/controllers/mastodon_api_controller.ex
@@ -119,6 +119,14 @@ defp add_if_present(
     end
   end
 
+  defp normalize_fields_attributes(fields) do
+    if Enum.all?(fields, &is_tuple/1) do
+      Enum.map(fields, fn {_, v} -> v end)
+    else
+      fields
+    end
+  end
+
   def update_credentials(%{assigns: %{user: user}} = conn, params) do
     original_user = user
 
@@ -143,6 +151,17 @@ def update_credentials(%{assigns: %{user: user}} = conn, params) do
       |> Enum.concat(Formatter.get_emoji_map(emojis_text))
       |> Enum.dedup()
 
+    params =
+      if Map.has_key?(params, "fields_attributes") do
+        Map.update!(params, "fields_attributes", fn fields ->
+          fields
+          |> normalize_fields_attributes()
+          |> Enum.filter(fn %{"name" => n} -> n != "" end)
+        end)
+      else
+        params
+      end
+
     info_params =
       [
         :no_rich_text,
@@ -159,12 +178,12 @@ 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 ->
+      |> add_if_present(params, "fields_attributes", :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, "fields_attributes", :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/test/web/mastodon_api/controllers/mastodon_api_controller/update_credentials_test.exs b/test/web/mastodon_api/controllers/mastodon_api_controller/update_credentials_test.exs
index 87ee82050..56a8f1716 100644
--- a/test/web/mastodon_api/controllers/mastodon_api_controller/update_credentials_test.exs
+++ b/test/web/mastodon_api/controllers/mastodon_api_controller/update_credentials_test.exs
@@ -313,7 +313,7 @@ test "update fields", %{conn: conn} do
       account =
         conn
         |> assign(:user, user)
-        |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+        |> patch("/api/v1/accounts/update_credentials", %{"fields_attributes" => fields})
         |> json_response(200)
 
       assert account["fields"] == [
@@ -329,6 +329,35 @@ test "update fields", %{conn: conn} do
                %{"name" => "link", "value" => "cofe.io"}
              ]
 
+      fields =
+        [
+          "fields_attributes[1][name]=link",
+          "fields_attributes[1][value]=cofe.io",
+          "fields_attributes[0][name]=<a href=\"http://google.com\">foo</a>",
+          "fields_attributes[0][value]=bar"
+        ]
+        |> Enum.join("&")
+
+      account =
+        conn
+        |> put_req_header("content-type", "application/x-www-form-urlencoded")
+        |> assign(:user, user)
+        |> patch("/api/v1/accounts/update_credentials", 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" => "bar"
+               },
+               %{"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])
 
@@ -339,7 +368,7 @@ test "update fields", %{conn: conn} do
       assert %{"error" => "Invalid request"} ==
                conn
                |> assign(:user, user)
-               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> patch("/api/v1/accounts/update_credentials", %{"fields_attributes" => fields})
                |> json_response(403)
 
       long_name = Enum.map(0..name_limit, fn _ -> "x" end) |> Enum.join()
@@ -349,7 +378,7 @@ test "update fields", %{conn: conn} do
       assert %{"error" => "Invalid request"} ==
                conn
                |> assign(:user, user)
-               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> patch("/api/v1/accounts/update_credentials", %{"fields_attributes" => fields})
                |> json_response(403)
 
       Pleroma.Config.put([:instance, :max_account_fields], 1)
@@ -362,8 +391,23 @@ test "update fields", %{conn: conn} do
       assert %{"error" => "Invalid request"} ==
                conn
                |> assign(:user, user)
-               |> patch("/api/v1/accounts/update_credentials", %{"fields" => fields})
+               |> patch("/api/v1/accounts/update_credentials", %{"fields_attributes" => fields})
                |> json_response(403)
+
+      fields = [
+        %{"name" => "foo", "value" => ""},
+        %{"name" => "", "value" => "bar"}
+      ]
+
+      account =
+        conn
+        |> assign(:user, user)
+        |> patch("/api/v1/accounts/update_credentials", %{"fields_attributes" => fields})
+        |> json_response(200)
+
+      assert account["fields"] == [
+               %{"name" => "foo", "value" => ""}
+             ]
     end
   end
 end