diff --git a/config/description.exs b/config/description.exs
index 2623e3683..37cb548ff 100644
--- a/config/description.exs
+++ b/config/description.exs
@@ -1483,14 +1483,12 @@
   # %{
   #   group: :pleroma,
   #   key: :mrf_user_allowlist,
-  #   type: :group,
+  #   type: :map,
   #   description:
   #     "The keys in this section are the domain names that the policy should apply to." <>
   #       " Each key should be assigned a list of users that should be allowed through by their ActivityPub ID",
-  #   children: [
-  #     ["example.org": ["https://example.org/users/admin"]],
   #     suggestions: [
-  #       ["example.org": ["https://example.org/users/admin"]]
+  #       %{"example.org" => ["https://example.org/users/admin"]}
   #     ]
   #   ]
   # },
diff --git a/docs/configuration/cheatsheet.md b/docs/configuration/cheatsheet.md
index 4012fe9b1..5d3f49401 100644
--- a/docs/configuration/cheatsheet.md
+++ b/docs/configuration/cheatsheet.md
@@ -133,8 +133,9 @@ their ActivityPub ID.
 An example:
 
 ```elixir
-config :pleroma, :mrf_user_allowlist,
-  "example.org": ["https://example.org/users/admin"]
+config :pleroma, :mrf_user_allowlist, %{
+  "example.org" => ["https://example.org/users/admin"]
+}
 ```
 
 #### :mrf_object_age
diff --git a/lib/pleroma/config/deprecation_warnings.ex b/lib/pleroma/config/deprecation_warnings.ex
index c39a8984b..b68ded01f 100644
--- a/lib/pleroma/config/deprecation_warnings.ex
+++ b/lib/pleroma/config/deprecation_warnings.ex
@@ -4,9 +4,10 @@
 
 defmodule Pleroma.Config.DeprecationWarnings do
   require Logger
+  alias Pleroma.Config
 
   def check_hellthread_threshold do
-    if Pleroma.Config.get([:mrf_hellthread, :threshold]) do
+    if Config.get([:mrf_hellthread, :threshold]) do
       Logger.warn("""
       !!!DEPRECATION WARNING!!!
       You are using the old configuration mechanism for the hellthread filter. Please check config.md.
@@ -14,7 +15,29 @@ def check_hellthread_threshold do
     end
   end
 
+  def mrf_user_allowlist do
+    config = Config.get(:mrf_user_allowlist)
+
+    if config && Enum.any?(config, fn {k, _} -> is_atom(k) end) do
+      rewritten =
+        Enum.reduce(Config.get(:mrf_user_allowlist), Map.new(), fn {k, v}, acc ->
+          Map.put(acc, to_string(k), v)
+        end)
+
+      Config.put(:mrf_user_allowlist, rewritten)
+
+      Logger.error("""
+      !!!DEPRECATION WARNING!!!
+      As of Pleroma 2.0.7, the `mrf_user_allowlist` setting changed of format.
+      Pleroma 2.1 will remove support for the old format. Please change your configuration to match this:
+
+      config :pleroma, :mrf_user_allowlist, #{inspect(rewritten, pretty: true)}
+      """)
+    end
+  end
+
   def warn do
     check_hellthread_threshold()
+    mrf_user_allowlist()
   end
 end
diff --git a/lib/pleroma/web/activity_pub/mrf/user_allow_list_policy.ex b/lib/pleroma/web/activity_pub/mrf/user_allow_list_policy.ex
index a927a4ed8..651aed70f 100644
--- a/lib/pleroma/web/activity_pub/mrf/user_allow_list_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/user_allow_list_policy.ex
@@ -24,7 +24,7 @@ def filter(%{"actor" => actor} = object) do
 
     allow_list =
       Config.get(
-        [:mrf_user_allowlist, String.to_atom(actor_info.host)],
+        [:mrf_user_allowlist, actor_info.host],
         []
       )
 
diff --git a/test/web/activity_pub/mrf/user_allowlist_policy_test.exs b/test/web/activity_pub/mrf/user_allowlist_policy_test.exs
index 87c9e1b29..7dd03870b 100644
--- a/test/web/activity_pub/mrf/user_allowlist_policy_test.exs
+++ b/test/web/activity_pub/mrf/user_allowlist_policy_test.exs
@@ -17,14 +17,14 @@ test "pass filter if allow list is empty" do
 
   test "pass filter if allow list isn't empty and user in allow list" do
     actor = insert(:user)
-    Pleroma.Config.put([:mrf_user_allowlist, :localhost], [actor.ap_id, "test-ap-id"])
+    Pleroma.Config.put([:mrf_user_allowlist], %{"localhost" => [actor.ap_id, "test-ap-id"]})
     message = %{"actor" => actor.ap_id}
     assert UserAllowListPolicy.filter(message) == {:ok, message}
   end
 
   test "rejected if allow list isn't empty and user not in allow list" do
     actor = insert(:user)
-    Pleroma.Config.put([:mrf_user_allowlist, :localhost], ["test-ap-id"])
+    Pleroma.Config.put([:mrf_user_allowlist], %{"localhost" => ["test-ap-id"]})
     message = %{"actor" => actor.ap_id}
     assert UserAllowListPolicy.filter(message) == {:reject, nil}
   end