diff --git a/lib/pleroma/web/common_api/activity_draft.ex b/lib/pleroma/web/common_api/activity_draft.ex
index 8668b600e..80a9fa7bb 100644
--- a/lib/pleroma/web/common_api/activity_draft.ex
+++ b/lib/pleroma/web/common_api/activity_draft.ex
@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.CommonAPI.ActivityDraft do
   alias Pleroma.Activity
   alias Pleroma.Conversation.Participation
+  alias Pleroma.Object
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.CommonAPI.Utils
 
@@ -186,6 +187,32 @@ defp sensitive(draft) do
   defp object(draft) do
     emoji = Map.merge(Pleroma.Emoji.Formatter.get_emoji_map(draft.full_payload), draft.emoji)
 
+    # Sometimes people create posts with subject containing emoji,
+    # since subjects are usually copied this will result in a broken
+    # subject when someone replies from an instance that does not have
+    # the emoji or has it under different shortcode. This is an attempt
+    # to mitigate this by copying emoji from inReplyTo if they are present
+    # in the subject.
+    summary_emoji =
+      with %Activity{} <- draft.in_reply_to,
+           %Object{data: %{"tag" => [_ | _] = tag}} <- Object.normalize(draft.in_reply_to) do
+        Enum.reduce(tag, %{}, fn
+          %{"type" => "Emoji", "name" => name, "icon" => %{"url" => url}}, acc ->
+            if String.contains?(draft.summary, name) do
+              Map.put(acc, name, url)
+            else
+              acc
+            end
+
+          _, acc ->
+            acc
+        end)
+      else
+        _ -> %{}
+      end
+
+    emoji = Map.merge(emoji, summary_emoji)
+
     object =
       Utils.make_note_data(draft)
       |> Map.put("emoji", emoji)
diff --git a/test/fixtures/tesla_mock/emoji-in-summary.json b/test/fixtures/tesla_mock/emoji-in-summary.json
new file mode 100644
index 000000000..f77c6e2e8
--- /dev/null
+++ b/test/fixtures/tesla_mock/emoji-in-summary.json
@@ -0,0 +1,49 @@
+{
+  "@context": [
+    "https://www.w3.org/ns/activitystreams",
+    "https://patch.cx/schemas/litepub-0.1.jsonld",
+    {
+      "@language": "und"
+    }
+  ],
+  "actor": "https://patch.cx/users/rin",
+  "attachment": [],
+  "attributedTo": "https://patch.cx/users/rin",
+  "cc": [
+    "https://patch.cx/users/rin/followers"
+  ],
+  "content": ":joker_disapprove: <br><br>just grabbing a test fixture, nevermind me",
+  "context": "https://patch.cx/contexts/2c3ce4b4-18b1-4b1a-8965-3932027b5326",
+  "conversation": "https://patch.cx/contexts/2c3ce4b4-18b1-4b1a-8965-3932027b5326",
+  "id": "https://patch.cx/objects/a399c28e-c821-4820-bc3e-4afeb044c16f",
+  "published": "2021-03-22T16:54:46.461939Z",
+  "sensitive": null,
+  "source": ":joker_disapprove: \r\n\r\njust grabbing a test fixture, nevermind me",
+  "summary": ":joker_smile: ",
+  "tag": [
+    {
+      "icon": {
+        "type": "Image",
+        "url": "https://patch.cx/emoji/custom/joker_disapprove.png"
+      },
+      "id": "https://patch.cx/emoji/custom/joker_disapprove.png",
+      "name": ":joker_disapprove:",
+      "type": "Emoji",
+      "updated": "1970-01-01T00:00:00Z"
+    },
+    {
+      "icon": {
+        "type": "Image",
+        "url": "https://patch.cx/emoji/custom/joker_smile.png"
+      },
+      "id": "https://patch.cx/emoji/custom/joker_smile.png",
+      "name": ":joker_smile:",
+      "type": "Emoji",
+      "updated": "1970-01-01T00:00:00Z"
+    }
+  ],
+  "to": [
+    "https://www.w3.org/ns/activitystreams#Public"
+  ],
+  "type": "Note"
+}
diff --git a/test/pleroma/web/common_api_test.exs b/test/pleroma/web/common_api_test.exs
index 9d005697c..6619f8fc8 100644
--- a/test/pleroma/web/common_api_test.exs
+++ b/test/pleroma/web/common_api_test.exs
@@ -25,6 +25,11 @@ defmodule Pleroma.Web.CommonAPITest do
 
   require Pleroma.Constants
 
+  setup_all do
+    Tesla.Mock.mock_global(fn env -> apply(HttpRequestMock, :request, [env]) end)
+    :ok
+  end
+
   setup do: clear_config([:instance, :safe_dm_mentions])
   setup do: clear_config([:instance, :limit])
   setup do: clear_config([:instance, :max_pinned_statuses])
@@ -517,6 +522,27 @@ test "it adds an emoji on an external site" do
       assert url == "#{Pleroma.Web.base_url()}/emoji/blank.png"
     end
 
+    test "it copies emoji from the subject of the parent post" do
+      %Object{} =
+        object =
+        Object.normalize("https://patch.cx/objects/a399c28e-c821-4820-bc3e-4afeb044c16f",
+          fetch: true
+        )
+
+      activity = Activity.get_create_by_object_ap_id(object.data["id"])
+      user = insert(:user)
+
+      {:ok, reply_activity} =
+        CommonAPI.post(user, %{
+          in_reply_to_id: activity.id,
+          status: ":joker_disapprove:",
+          spoiler_text: ":joker_smile:"
+        })
+
+      assert Object.normalize(reply_activity).data["emoji"][":joker_smile:"]
+      refute Object.normalize(reply_activity).data["emoji"][":joker_disapprove:"]
+    end
+
     test "deactivated users can't post" do
       user = insert(:user, is_active: false)
       assert {:error, _} = CommonAPI.post(user, %{status: "ye"})
diff --git a/test/support/http_request_mock.ex b/test/support/http_request_mock.ex
index 1e98020f0..eb692fab5 100644
--- a/test/support/http_request_mock.ex
+++ b/test/support/http_request_mock.ex
@@ -1278,6 +1278,15 @@ def get("https://osada.macgirvin.com/", _, "", [{"accept", "text/html"}]) do
      }}
   end
 
+  def get("https://patch.cx/objects/a399c28e-c821-4820-bc3e-4afeb044c16f", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/tesla_mock/emoji-in-summary.json"),
+       headers: activitypub_object_headers()
+     }}
+  end
+
   def get(url, query, body, headers) do
     {:error,
      "Mock response not implemented for GET #{inspect(url)}, #{query}, #{inspect(body)}, #{