diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 1d70a37ef..9d5c61e79 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -1309,7 +1309,8 @@ def block(%User{} = blocker, %User{} = blocked) do
 
     unsubscribe(blocked, blocker)
 
-    if following?(blocked, blocker), do: unfollow(blocked, blocker)
+    unfollowing_blocked = Config.get([:activitypub, :unfollow_blocked], true)
+    if unfollowing_blocked && following?(blocked, blocker), do: unfollow(blocked, blocker)
 
     {:ok, blocker} = update_follower_count(blocker)
     {:ok, blocker, _} = Participation.mark_all_as_read(blocker, blocked)
@@ -1527,8 +1528,7 @@ def perform(:blocks_import, %User{} = blocker, blocked_identifiers)
       blocked_identifiers,
       fn blocked_identifier ->
         with {:ok, %User{} = blocked} <- get_or_fetch(blocked_identifier),
-             {:ok, _user_block} <- block(blocker, blocked),
-             {:ok, _} <- ActivityPub.block(blocker, blocked) do
+             {:ok, _block} <- CommonAPI.block(blocker, blocked) do
           blocked
         else
           err ->
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 7cd3eab39..05bd824f5 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -366,33 +366,6 @@ defp do_unfollow(follower, followed, activity_id, local) do
     end
   end
 
-  @spec block(User.t(), User.t(), String.t() | nil, boolean()) ::
-          {:ok, Activity.t()} | {:error, any()}
-  def block(blocker, blocked, activity_id \\ nil, local \\ true) do
-    with {:ok, result} <-
-           Repo.transaction(fn -> do_block(blocker, blocked, activity_id, local) end) do
-      result
-    end
-  end
-
-  defp do_block(blocker, blocked, activity_id, local) do
-    unfollow_blocked = Config.get([:activitypub, :unfollow_blocked])
-
-    if unfollow_blocked and fetch_latest_follow(blocker, blocked) do
-      unfollow(blocker, blocked, nil, local)
-    end
-
-    block_data = make_block_data(blocker, blocked, activity_id)
-
-    with {:ok, activity} <- insert(block_data, local),
-         _ <- notify_and_stream(activity),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity}
-    else
-      {:error, error} -> Repo.rollback(error)
-    end
-  end
-
   @spec flag(map()) :: {:ok, Activity.t()} | {:error, any()}
   def flag(
         %{
diff --git a/lib/pleroma/web/activity_pub/builder.ex b/lib/pleroma/web/activity_pub/builder.ex
index 135a5c431..cabc28de9 100644
--- a/lib/pleroma/web/activity_pub/builder.ex
+++ b/lib/pleroma/web/activity_pub/builder.ex
@@ -138,6 +138,18 @@ def update(actor, object) do
      }, []}
   end
 
+  @spec block(User.t(), User.t()) :: {:ok, map(), keyword()}
+  def block(blocker, blocked) do
+    {:ok,
+     %{
+       "id" => Utils.generate_activity_id(),
+       "type" => "Block",
+       "actor" => blocker.ap_id,
+       "object" => blocked.ap_id,
+       "to" => [blocked.ap_id]
+     }, []}
+  end
+
   @spec announce(User.t(), Object.t(), keyword()) :: {:ok, map(), keyword()}
   def announce(actor, object, options \\ []) do
     public? = Keyword.get(options, :public, false)
diff --git a/lib/pleroma/web/activity_pub/object_validator.ex b/lib/pleroma/web/activity_pub/object_validator.ex
index 2c657b467..bb6324460 100644
--- a/lib/pleroma/web/activity_pub/object_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validator.ex
@@ -13,6 +13,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
   alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ObjectValidators.AnnounceValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.BlockValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator
@@ -24,6 +25,25 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
   @spec validate(map(), keyword()) :: {:ok, map(), keyword()} | {:error, any()}
   def validate(object, meta)
 
+  def validate(%{"type" => "Block"} = block_activity, meta) do
+    with {:ok, block_activity} <-
+           block_activity
+           |> BlockValidator.cast_and_validate()
+           |> Ecto.Changeset.apply_action(:insert) do
+      block_activity = stringify_keys(block_activity)
+      outgoing_blocks = Pleroma.Config.get([:activitypub, :outgoing_blocks])
+
+      meta =
+        if !outgoing_blocks do
+          Keyword.put(meta, :do_not_federate, true)
+        else
+          meta
+        end
+
+      {:ok, block_activity, meta}
+    end
+  end
+
   def validate(%{"type" => "Update"} = update_activity, meta) do
     with {:ok, update_activity} <-
            update_activity
diff --git a/lib/pleroma/web/activity_pub/object_validators/block_validator.ex b/lib/pleroma/web/activity_pub/object_validators/block_validator.ex
new file mode 100644
index 000000000..1dde77198
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/block_validator.ex
@@ -0,0 +1,42 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.BlockValidator do
+  use Ecto.Schema
+
+  alias Pleroma.EctoType.ActivityPub.ObjectValidators
+
+  import Ecto.Changeset
+  import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
+
+  @primary_key false
+
+  embedded_schema do
+    field(:id, ObjectValidators.ObjectID, primary_key: true)
+    field(:type, :string)
+    field(:actor, ObjectValidators.ObjectID)
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
+    field(:object, ObjectValidators.ObjectID)
+  end
+
+  def cast_data(data) do
+    %__MODULE__{}
+    |> cast(data, __schema__(:fields))
+  end
+
+  def validate_data(cng) do
+    cng
+    |> validate_required([:id, :type, :actor, :to, :cc, :object])
+    |> validate_inclusion(:type, ["Block"])
+    |> validate_actor_presence()
+    |> validate_actor_presence(field_name: :object)
+  end
+
+  def cast_and_validate(data) do
+    data
+    |> cast_data
+    |> validate_data
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/side_effects.ex b/lib/pleroma/web/activity_pub/side_effects.ex
index de143b8f0..5cc2eb378 100644
--- a/lib/pleroma/web/activity_pub/side_effects.ex
+++ b/lib/pleroma/web/activity_pub/side_effects.ex
@@ -20,6 +20,21 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
 
   def handle(object, meta \\ [])
 
+  # Tasks this handles:
+  # - Unfollow and block
+  def handle(
+        %{data: %{"type" => "Block", "object" => blocked_user, "actor" => blocking_user}} =
+          object,
+        meta
+      ) do
+    with %User{} = blocker <- User.get_cached_by_ap_id(blocking_user),
+         %User{} = blocked <- User.get_cached_by_ap_id(blocked_user) do
+      User.block(blocker, blocked)
+    end
+
+    {:ok, object, meta}
+  end
+
   # Tasks this handles:
   # - Update the user
   #
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 4e318e89c..278fbbeab 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -673,7 +673,7 @@ def handle_incoming(
   end
 
   def handle_incoming(%{"type" => type} = data, _options)
-      when type in ["Like", "EmojiReact", "Announce"] do
+      when type in ~w{Like EmojiReact Announce} do
     with :ok <- ObjectValidator.fetch_actor_and_object(data),
          {:ok, activity, _meta} <-
            Pipeline.common_pipeline(data, local: false) do
@@ -684,9 +684,10 @@ def handle_incoming(%{"type" => type} = data, _options)
   end
 
   def handle_incoming(
-        %{"type" => "Update"} = data,
+        %{"type" => type} = data,
         _options
-      ) do
+      )
+      when type in ~w{Update Block} do
     with {:ok, %User{}} <- ObjectValidator.fetch_actor(data),
          {:ok, activity, _} <- Pipeline.common_pipeline(data, local: false) do
       {:ok, activity}
@@ -765,21 +766,6 @@ def handle_incoming(
     end
   end
 
-  def handle_incoming(
-        %{"type" => "Block", "object" => blocked, "actor" => blocker, "id" => id} = _data,
-        _options
-      ) do
-    with %User{local: true} = blocked = User.get_cached_by_ap_id(blocked),
-         {:ok, %User{} = blocker} = User.get_or_fetch_by_ap_id(blocker),
-         {:ok, activity} <- ActivityPub.block(blocker, blocked, id, false) do
-      User.unfollow(blocker, blocked)
-      User.block(blocker, blocked)
-      {:ok, activity}
-    else
-      _e -> :error
-    end
-  end
-
   def handle_incoming(
         %{
           "type" => "Move",
diff --git a/lib/pleroma/web/common_api/common_api.ex b/lib/pleroma/web/common_api/common_api.ex
index 04e081a8e..fd7149079 100644
--- a/lib/pleroma/web/common_api/common_api.ex
+++ b/lib/pleroma/web/common_api/common_api.ex
@@ -25,6 +25,13 @@ defmodule Pleroma.Web.CommonAPI do
   require Pleroma.Constants
   require Logger
 
+  def block(blocker, blocked) do
+    with {:ok, block_data, _} <- Builder.block(blocker, blocked),
+         {:ok, block, _} <- Pipeline.common_pipeline(block_data, local: true) do
+      {:ok, block}
+    end
+  end
+
   def post_chat_message(%User{} = user, %User{} = recipient, content, opts \\ []) do
     with maybe_attachment <- opts[:media_id] && Object.get_by_id(opts[:media_id]),
          :ok <- validate_chat_content_length(content, !!maybe_attachment),
diff --git a/lib/pleroma/web/mastodon_api/controllers/account_controller.ex b/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
index 7a88a847c..b5008d69b 100644
--- a/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
+++ b/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
@@ -385,8 +385,7 @@ def unmute(%{assigns: %{user: muter, account: muted}} = conn, _params) do
 
   @doc "POST /api/v1/accounts/:id/block"
   def block(%{assigns: %{user: blocker, account: blocked}} = conn, _params) do
-    with {:ok, _user_block} <- User.block(blocker, blocked),
-         {:ok, _activity} <- ActivityPub.block(blocker, blocked) do
+    with {:ok, _activity} <- CommonAPI.block(blocker, blocked) do
       render(conn, "relationship.json", user: blocker, target: blocked)
     else
       {:error, message} -> json_response(conn, :forbidden, %{error: message})
diff --git a/test/web/activity_pub/activity_pub_test.exs b/test/web/activity_pub/activity_pub_test.exs
index be7ab2ae4..575e0c5db 100644
--- a/test/web/activity_pub/activity_pub_test.exs
+++ b/test/web/activity_pub/activity_pub_test.exs
@@ -992,54 +992,6 @@ test "creates an undo activity for a pending follow request" do
     end
   end
 
-  describe "blocking" do
-    test "reverts block activity on error" do
-      [blocker, blocked] = insert_list(2, :user)
-
-      with_mock(Utils, [:passthrough], maybe_federate: fn _ -> {:error, :reverted} end) do
-        assert {:error, :reverted} = ActivityPub.block(blocker, blocked)
-      end
-
-      assert Repo.aggregate(Activity, :count, :id) == 0
-      assert Repo.aggregate(Object, :count, :id) == 0
-    end
-
-    test "creates a block activity" do
-      clear_config([:instance, :federating], true)
-      blocker = insert(:user)
-      blocked = insert(:user)
-
-      with_mock Pleroma.Web.Federator,
-        publish: fn _ -> nil end do
-        {:ok, activity} = ActivityPub.block(blocker, blocked)
-
-        assert activity.data["type"] == "Block"
-        assert activity.data["actor"] == blocker.ap_id
-        assert activity.data["object"] == blocked.ap_id
-
-        assert called(Pleroma.Web.Federator.publish(activity))
-      end
-    end
-
-    test "works with outgoing blocks disabled, but doesn't federate" do
-      clear_config([:instance, :federating], true)
-      clear_config([:activitypub, :outgoing_blocks], false)
-      blocker = insert(:user)
-      blocked = insert(:user)
-
-      with_mock Pleroma.Web.Federator,
-        publish: fn _ -> nil end do
-        {:ok, activity} = ActivityPub.block(blocker, blocked)
-
-        assert activity.data["type"] == "Block"
-        assert activity.data["actor"] == blocker.ap_id
-        assert activity.data["object"] == blocked.ap_id
-
-        refute called(Pleroma.Web.Federator.publish(:_))
-      end
-    end
-  end
-
   describe "timeline post-processing" do
     test "it filters broken threads" do
       user1 = insert(:user)
diff --git a/test/web/activity_pub/object_validator_test.exs b/test/web/activity_pub/object_validator_test.exs
index 770a8dcf8..f38bf7e08 100644
--- a/test/web/activity_pub/object_validator_test.exs
+++ b/test/web/activity_pub/object_validator_test.exs
@@ -654,4 +654,31 @@ test "returns an error if the object can't be updated by the actor", %{
       assert {:error, _cng} = ObjectValidator.validate(update, [])
     end
   end
+
+  describe "blocks" do
+    setup do
+      user = insert(:user, local: false)
+      blocked = insert(:user)
+
+      {:ok, valid_block, []} = Builder.block(user, blocked)
+
+      %{user: user, valid_block: valid_block}
+    end
+
+    test "validates a basic object", %{
+      valid_block: valid_block
+    } do
+      assert {:ok, _block, []} = ObjectValidator.validate(valid_block, [])
+    end
+
+    test "returns an error if we don't know the blocked user", %{
+      valid_block: valid_block
+    } do
+      block =
+        valid_block
+        |> Map.put("object", "https://gensokyo.2hu/users/raymoo")
+
+      assert {:error, _cng} = ObjectValidator.validate(block, [])
+    end
+  end
 end
diff --git a/test/web/activity_pub/side_effects_test.exs b/test/web/activity_pub/side_effects_test.exs
index 12c9ef1da..af27c34b4 100644
--- a/test/web/activity_pub/side_effects_test.exs
+++ b/test/web/activity_pub/side_effects_test.exs
@@ -64,6 +64,47 @@ test "it streams out notifications and streams" do
     end
   end
 
+  describe "blocking users" do
+    setup do
+      user = insert(:user)
+      blocked = insert(:user)
+      User.follow(blocked, user)
+      User.follow(user, blocked)
+
+      {:ok, block_data, []} = Builder.block(user, blocked)
+      {:ok, block, _meta} = ActivityPub.persist(block_data, local: true)
+
+      %{user: user, blocked: blocked, block: block}
+    end
+
+    test "it unfollows and blocks", %{user: user, blocked: blocked, block: block} do
+      assert User.following?(user, blocked)
+      assert User.following?(blocked, user)
+
+      {:ok, _, _} = SideEffects.handle(block)
+
+      refute User.following?(user, blocked)
+      refute User.following?(blocked, user)
+      assert User.blocks?(user, blocked)
+    end
+
+    test "it blocks but does not unfollow if the relevant setting is set", %{
+      user: user,
+      blocked: blocked,
+      block: block
+    } do
+      clear_config([:activitypub, :unfollow_blocked], false)
+      assert User.following?(user, blocked)
+      assert User.following?(blocked, user)
+
+      {:ok, _, _} = SideEffects.handle(block)
+
+      refute User.following?(user, blocked)
+      assert User.following?(blocked, user)
+      assert User.blocks?(user, blocked)
+    end
+  end
+
   describe "update users" do
     setup do
       user = insert(:user)
@@ -242,8 +283,7 @@ test "when activation is required", %{delete: delete, user: user} do
       {:ok, like} = CommonAPI.favorite(user, post.id)
       {:ok, reaction} = CommonAPI.react_with_emoji(post.id, user, "👍")
       {:ok, announce} = CommonAPI.repeat(post.id, user)
-      {:ok, block} = ActivityPub.block(user, poster)
-      User.block(user, poster)
+      {:ok, block} = CommonAPI.block(user, poster)
 
       {:ok, undo_data, _meta} = Builder.undo(user, like)
       {:ok, like_undo, _meta} = ActivityPub.persist(undo_data, local: true)
diff --git a/test/web/activity_pub/transmogrifier/block_handling_test.exs b/test/web/activity_pub/transmogrifier/block_handling_test.exs
new file mode 100644
index 000000000..71f1a0ed5
--- /dev/null
+++ b/test/web/activity_pub/transmogrifier/block_handling_test.exs
@@ -0,0 +1,63 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.Transmogrifier.BlockHandlingTest do
+  use Pleroma.DataCase
+
+  alias Pleroma.Activity
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.Transmogrifier
+
+  import Pleroma.Factory
+
+  test "it works for incoming blocks" do
+    user = insert(:user)
+
+    data =
+      File.read!("test/fixtures/mastodon-block-activity.json")
+      |> Poison.decode!()
+      |> Map.put("object", user.ap_id)
+
+    blocker = insert(:user, ap_id: data["actor"])
+
+    {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
+
+    assert data["type"] == "Block"
+    assert data["object"] == user.ap_id
+    assert data["actor"] == "http://mastodon.example.org/users/admin"
+
+    assert User.blocks?(blocker, user)
+  end
+
+  test "incoming blocks successfully tear down any follow relationship" do
+    blocker = insert(:user)
+    blocked = insert(:user)
+
+    data =
+      File.read!("test/fixtures/mastodon-block-activity.json")
+      |> Poison.decode!()
+      |> Map.put("object", blocked.ap_id)
+      |> Map.put("actor", blocker.ap_id)
+
+    {:ok, blocker} = User.follow(blocker, blocked)
+    {:ok, blocked} = User.follow(blocked, blocker)
+
+    assert User.following?(blocker, blocked)
+    assert User.following?(blocked, blocker)
+
+    {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
+
+    assert data["type"] == "Block"
+    assert data["object"] == blocked.ap_id
+    assert data["actor"] == blocker.ap_id
+
+    blocker = User.get_cached_by_ap_id(data["actor"])
+    blocked = User.get_cached_by_ap_id(data["object"])
+
+    assert User.blocks?(blocker, blocked)
+
+    refute User.following?(blocker, blocked)
+    refute User.following?(blocked, blocker)
+  end
+end
diff --git a/test/web/activity_pub/transmogrifier_test.exs b/test/web/activity_pub/transmogrifier_test.exs
index 100821056..6a53fd3f0 100644
--- a/test/web/activity_pub/transmogrifier_test.exs
+++ b/test/web/activity_pub/transmogrifier_test.exs
@@ -445,56 +445,6 @@ test "it works for incoming follows to locked account" do
       assert [^pending_follower] = User.get_follow_requests(user)
     end
 
-    test "it works for incoming blocks" do
-      user = insert(:user)
-
-      data =
-        File.read!("test/fixtures/mastodon-block-activity.json")
-        |> Poison.decode!()
-        |> Map.put("object", user.ap_id)
-
-      {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
-
-      assert data["type"] == "Block"
-      assert data["object"] == user.ap_id
-      assert data["actor"] == "http://mastodon.example.org/users/admin"
-
-      blocker = User.get_cached_by_ap_id(data["actor"])
-
-      assert User.blocks?(blocker, user)
-    end
-
-    test "incoming blocks successfully tear down any follow relationship" do
-      blocker = insert(:user)
-      blocked = insert(:user)
-
-      data =
-        File.read!("test/fixtures/mastodon-block-activity.json")
-        |> Poison.decode!()
-        |> Map.put("object", blocked.ap_id)
-        |> Map.put("actor", blocker.ap_id)
-
-      {:ok, blocker} = User.follow(blocker, blocked)
-      {:ok, blocked} = User.follow(blocked, blocker)
-
-      assert User.following?(blocker, blocked)
-      assert User.following?(blocked, blocker)
-
-      {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(data)
-
-      assert data["type"] == "Block"
-      assert data["object"] == blocked.ap_id
-      assert data["actor"] == blocker.ap_id
-
-      blocker = User.get_cached_by_ap_id(data["actor"])
-      blocked = User.get_cached_by_ap_id(data["object"])
-
-      assert User.blocks?(blocker, blocked)
-
-      refute User.following?(blocker, blocked)
-      refute User.following?(blocked, blocker)
-    end
-
     test "it works for incoming accepts which were pre-accepted" do
       follower = insert(:user)
       followed = insert(:user)
diff --git a/test/web/activity_pub/utils_test.exs b/test/web/activity_pub/utils_test.exs
index 15f03f193..2f9ecb5a3 100644
--- a/test/web/activity_pub/utils_test.exs
+++ b/test/web/activity_pub/utils_test.exs
@@ -27,16 +27,6 @@ test "fetches the latest Follow activity" do
     end
   end
 
-  describe "fetch the latest Block" do
-    test "fetches the latest Block activity" do
-      blocker = insert(:user)
-      blocked = insert(:user)
-      {:ok, activity} = ActivityPub.block(blocker, blocked)
-
-      assert activity == Utils.fetch_latest_block(blocker, blocked)
-    end
-  end
-
   describe "determine_explicit_mentions()" do
     test "works with an object that has mentions" do
       object = %{
@@ -344,9 +334,9 @@ test "fetches last block activities" do
       user1 = insert(:user)
       user2 = insert(:user)
 
-      assert {:ok, %Activity{} = _} = ActivityPub.block(user1, user2)
-      assert {:ok, %Activity{} = _} = ActivityPub.block(user1, user2)
-      assert {:ok, %Activity{} = activity} = ActivityPub.block(user1, user2)
+      assert {:ok, %Activity{} = _} = CommonAPI.block(user1, user2)
+      assert {:ok, %Activity{} = _} = CommonAPI.block(user1, user2)
+      assert {:ok, %Activity{} = activity} = CommonAPI.block(user1, user2)
 
       assert Utils.fetch_latest_block(user1, user2) == activity
     end
diff --git a/test/web/common_api/common_api_test.exs b/test/web/common_api/common_api_test.exs
index 6bd26050e..fc3bb845d 100644
--- a/test/web/common_api/common_api_test.exs
+++ b/test/web/common_api/common_api_test.exs
@@ -25,6 +25,52 @@ defmodule Pleroma.Web.CommonAPITest do
   setup do: clear_config([:instance, :limit])
   setup do: clear_config([:instance, :max_pinned_statuses])
 
+  describe "blocking" do
+    setup do
+      blocker = insert(:user)
+      blocked = insert(:user)
+      User.follow(blocker, blocked)
+      User.follow(blocked, blocker)
+      %{blocker: blocker, blocked: blocked}
+    end
+
+    test "it blocks and federates", %{blocker: blocker, blocked: blocked} do
+      clear_config([:instance, :federating], true)
+
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
+        assert {:ok, block} = CommonAPI.block(blocker, blocked)
+
+        assert block.local
+        assert User.blocks?(blocker, blocked)
+        refute User.following?(blocker, blocked)
+        refute User.following?(blocked, blocker)
+
+        assert called(Pleroma.Web.Federator.publish(block))
+      end
+    end
+
+    test "it blocks and does not federate if outgoing blocks are disabled", %{
+      blocker: blocker,
+      blocked: blocked
+    } do
+      clear_config([:instance, :federating], true)
+      clear_config([:activitypub, :outgoing_blocks], false)
+
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
+        assert {:ok, block} = CommonAPI.block(blocker, blocked)
+
+        assert block.local
+        assert User.blocks?(blocker, blocked)
+        refute User.following?(blocker, blocked)
+        refute User.following?(blocked, blocker)
+
+        refute called(Pleroma.Web.Federator.publish(block))
+      end
+    end
+  end
+
   describe "posting chat messages" do
     setup do: clear_config([:instance, :chat_limit])