diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6bd835a3d..dac61c174 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -44,6 +44,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Mix task to re-count statuses for all users (`mix pleroma.count_statuses`)
 - Support for `X-Forwarded-For` and similar HTTP headers which used by reverse proxies to pass a real user IP address to the backend. Must not be enabled unless your instance is behind at least one reverse proxy (such as Nginx, Apache HTTPD or Varnish Cache).
 - MRF: New module which handles incoming posts based on their age. By default, all incoming posts that are older than 2 days will be unlisted and not shown to their followers.
+- OAuth: admin scopes support (relevant setting: `[:auth, :enforce_oauth_admin_scope_usage]`).
 <details>
   <summary>API Changes</summary>
 
diff --git a/config/config.exs b/config/config.exs
index bf2b3f6e2..64397484e 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -560,7 +560,10 @@ config :ueberauth,
        base_path: "/oauth",
        providers: ueberauth_providers
 
-config :pleroma, :auth, oauth_consumer_strategies: oauth_consumer_strategies
+config :pleroma,
+       :auth,
+       enforce_oauth_admin_scope_usage: false,
+       oauth_consumer_strategies: oauth_consumer_strategies
 
 config :pleroma, Pleroma.Emails.Mailer, adapter: Swoosh.Adapters.Sendmail, enabled: false
 
diff --git a/config/description.exs b/config/description.exs
index 70e963399..45e4b43f1 100644
--- a/config/description.exs
+++ b/config/description.exs
@@ -2094,6 +2094,15 @@ config :pleroma, :config_description, [
     type: :group,
     description: "Authentication / authorization settings",
     children: [
+      %{
+        key: :enforce_oauth_admin_scope_usage,
+        type: :boolean,
+        description:
+          "OAuth admin scope requirement toggle. " <>
+            "If `true`, admin actions explicitly demand admin OAuth scope(s) presence in OAuth token " <>
+            "(client app must support admin scopes). If `false` and token doesn't have admin scope(s)," <>
+            "`is_admin` user flag grants access to admin-specific actions."
+      },
       %{
         key: :auth_template,
         type: :string,
diff --git a/lib/mix/tasks/pleroma/user.ex b/lib/mix/tasks/pleroma/user.ex
index 4e3b80db3..8c4739221 100644
--- a/lib/mix/tasks/pleroma/user.ex
+++ b/lib/mix/tasks/pleroma/user.ex
@@ -8,7 +8,6 @@ defmodule Mix.Tasks.Pleroma.User do
   alias Ecto.Changeset
   alias Pleroma.User
   alias Pleroma.UserInviteToken
-  alias Pleroma.Web.OAuth
 
   @shortdoc "Manages Pleroma users"
   @moduledoc File.read!("docs/administration/CLI_tasks/user.md")
@@ -354,8 +353,7 @@ defmodule Mix.Tasks.Pleroma.User do
     start_pleroma()
 
     with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
-      OAuth.Token.delete_user_tokens(user)
-      OAuth.Authorization.delete_user_authorizations(user)
+      User.global_sign_out(user)
 
       shell_info("#{nickname} signed out from all apps.")
     else
@@ -375,10 +373,7 @@ defmodule Mix.Tasks.Pleroma.User do
   end
 
   defp set_admin(user, value) do
-    {:ok, user} =
-      user
-      |> Changeset.change(%{is_admin: value})
-      |> User.update_and_set_cache()
+    {:ok, user} = User.admin_api_update(user, %{is_admin: value})
 
     shell_info("Admin status of #{user.nickname}: #{user.is_admin}")
     user
diff --git a/lib/pleroma/config.ex b/lib/pleroma/config.ex
index fcc039710..cadab2f15 100644
--- a/lib/pleroma/config.ex
+++ b/lib/pleroma/config.ex
@@ -65,4 +65,11 @@ defmodule Pleroma.Config do
   def oauth_consumer_strategies, do: get([:auth, :oauth_consumer_strategies], [])
 
   def oauth_consumer_enabled?, do: oauth_consumer_strategies() != []
+
+  def enforce_oauth_admin_scope_usage?, do: !!get([:auth, :enforce_oauth_admin_scope_usage])
+
+  def oauth_admin_scopes(scope) do
+    ["admin:#{scope}"] ++
+      if enforce_oauth_admin_scope_usage?(), do: [], else: [scope]
+  end
 end
diff --git a/lib/pleroma/plugs/user_is_admin_plug.ex b/lib/pleroma/plugs/user_is_admin_plug.ex
index ee808f31f..8814556f1 100644
--- a/lib/pleroma/plugs/user_is_admin_plug.ex
+++ b/lib/pleroma/plugs/user_is_admin_plug.ex
@@ -5,19 +5,39 @@
 defmodule Pleroma.Plugs.UserIsAdminPlug do
   import Pleroma.Web.TranslationHelpers
   import Plug.Conn
+
   alias Pleroma.User
+  alias Pleroma.Web.OAuth
 
   def init(options) do
     options
   end
 
-  def call(%{assigns: %{user: %User{is_admin: true}}} = conn, _) do
-    conn
+  def call(%Plug.Conn{assigns: %{token: %OAuth.Token{scopes: oauth_scopes} = _token}} = conn, _) do
+    if OAuth.Scopes.contains_admin_scopes?(oauth_scopes) do
+      # Note: checking for _any_ admin scope presence, not necessarily fitting requested action.
+      #   Thus, controller must explicitly invoke OAuthScopesPlug to verify scope requirements.
+      conn
+    else
+      fail(conn)
+    end
+  end
+
+  unless Pleroma.Config.enforce_oauth_admin_scope_usage?() do
+    # To do: once AdminFE makes use of "admin" scope, disable the following func definition
+    #   (fail on no admin scope(s) in token even if `is_admin` is true)
+    def call(%Plug.Conn{assigns: %{user: %User{is_admin: true}}} = conn, _) do
+      conn
+    end
   end
 
   def call(conn, _) do
+    fail(conn)
+  end
+
+  defp fail(conn) do
     conn
-    |> render_error(:forbidden, "User is not admin.")
-    |> halt
+    |> render_error(:forbidden, "User is not an admin or OAuth admin scope is not granted.")
+    |> halt()
   end
 end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index fcb1d5143..d05dccd3d 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -1732,13 +1732,27 @@ defmodule Pleroma.User do
   end
 
   def admin_api_update(user, params) do
-    user
-    |> cast(params, [
-      :is_moderator,
-      :is_admin,
-      :show_role
-    ])
-    |> update_and_set_cache()
+    changeset =
+      cast(user, params, [
+        :is_moderator,
+        :is_admin,
+        :show_role
+      ])
+
+    with {:ok, updated_user} <- update_and_set_cache(changeset) do
+      if user.is_admin && !updated_user.is_admin do
+        # Tokens & authorizations containing any admin scopes must be revoked (revoking all)
+        global_sign_out(user)
+      end
+
+      {:ok, updated_user}
+    end
+  end
+
+  @doc "Signs user out of all applications"
+  def global_sign_out(user) do
+    OAuth.Authorization.delete_user_authorizations(user)
+    OAuth.Token.delete_user_tokens(user)
   end
 
   def mascot_update(user, url) do
diff --git a/lib/pleroma/web/admin_api/admin_api_controller.ex b/lib/pleroma/web/admin_api/admin_api_controller.ex
index 01cd12c96..f9ace00d7 100644
--- a/lib/pleroma/web/admin_api/admin_api_controller.ex
+++ b/lib/pleroma/web/admin_api/admin_api_controller.ex
@@ -30,13 +30,13 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:read:accounts", "read:accounts"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("read:accounts")}
     when action in [:list_users, :user_show, :right_get, :invites]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:write:accounts", "write:accounts"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("write:accounts")}
     when action in [
            :get_invite_token,
            :revoke_invite,
@@ -58,35 +58,37 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:read:reports", "read:reports"]} when action in [:list_reports, :report_show]
+    %{scopes: Pleroma.Config.oauth_admin_scopes("read:reports")}
+    when action in [:list_reports, :report_show]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:reports", "write:reports"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("write:reports")}
     when action in [:report_update_state, :report_respond]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:read:statuses", "read:statuses"]} when action == :list_user_statuses
+    %{scopes: Pleroma.Config.oauth_admin_scopes("read:statuses")}
+    when action == :list_user_statuses
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:write:statuses", "write:statuses"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("write:statuses")}
     when action in [:status_update, :status_delete]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:read", "read"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("read")}
     when action in [:config_show, :migrate_to_db, :migrate_from_db, :list_log]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:write", "write"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("write")}
     when action in [:relay_follow, :relay_unfollow, :config_update]
   )
 
diff --git a/lib/pleroma/web/oauth/scopes.ex b/lib/pleroma/web/oauth/scopes.ex
index 0c8796ecb..5e04652c2 100644
--- a/lib/pleroma/web/oauth/scopes.ex
+++ b/lib/pleroma/web/oauth/scopes.ex
@@ -83,7 +83,7 @@ defmodule Pleroma.Web.OAuth.Scopes do
     end
   end
 
-  defp contains_admin_scopes?(scopes) do
+  def contains_admin_scopes?(scopes) do
     scopes
     |> OAuthScopesPlug.filter_descendants(["admin"])
     |> Enum.any?()
diff --git a/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex b/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
index 1e8c62e3a..6f286032e 100644
--- a/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
+++ b/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
@@ -7,7 +7,7 @@ defmodule Pleroma.Web.PleromaAPI.EmojiAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["admin:write", "write"]}
+    %{scopes: Pleroma.Config.oauth_admin_scopes("write")}
     when action in [
            :create,
            :delete,
diff --git a/test/web/admin_api/admin_api_controller_test.exs b/test/web/admin_api/admin_api_controller_test.exs
index 3a4c4d65c..fd179e8c2 100644
--- a/test/web/admin_api/admin_api_controller_test.exs
+++ b/test/web/admin_api/admin_api_controller_test.exs
@@ -1537,7 +1537,8 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIControllerTest do
         |> assign(:user, user)
         |> get("/api/pleroma/admin/reports")
 
-      assert json_response(conn, :forbidden) == %{"error" => "User is not admin."}
+      assert json_response(conn, :forbidden) ==
+               %{"error" => "User is not an admin or OAuth admin scope is not granted."}
     end
 
     test "returns 403 when requested by anonymous" do