diff --git a/lib/pleroma/web/activity_pub/mrf/steal_emoji_policy.ex b/lib/pleroma/web/activity_pub/mrf/steal_emoji_policy.ex
index 3e1dc7d43..6c43afa58 100644
--- a/lib/pleroma/web/activity_pub/mrf/steal_emoji_policy.ex
+++ b/lib/pleroma/web/activity_pub/mrf/steal_emoji_policy.ex
@@ -77,7 +77,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.StealEmojiPolicy do
       new_emojis =
         foreign_emojis
         |> Enum.reject(fn {shortcode, _url} -> shortcode in installed_emoji end)
-        |> Enum.reject(fn {shortcode, _url} -> String.contains?(shortcode, ["/", "\\"]) end)
+        |> Enum.reject(fn {shortcode, _url} -> String.contains?(shortcode, ["/", "\\", ".", ":"]) end)
         |> Enum.filter(fn {shortcode, _url} ->
           reject_emoji? =
             [:mrf_steal_emoji, :rejected_shortcodes]