diff --git a/changelog.d/notifications.fix b/changelog.d/notifications.fix
new file mode 100644
index 000000000..a2d2eaea9
--- /dev/null
+++ b/changelog.d/notifications.fix
@@ -0,0 +1 @@
+Notifications: improve performance by filtering on users table instead of activities table
\ No newline at end of file
diff --git a/lib/pleroma/following_relationship.ex b/lib/pleroma/following_relationship.ex
index 15664c876..f38c2fce9 100644
--- a/lib/pleroma/following_relationship.ex
+++ b/lib/pleroma/following_relationship.ex
@@ -241,13 +241,13 @@ defmodule Pleroma.FollowingRelationship do
   end
 
   @doc """
-  For a query with joined activity,
-  keeps rows where activity's actor is followed by user -or- is NOT domain-blocked by user.
+  For a query with joined activity's actor,
+  keeps rows where actor is followed by user -or- is NOT domain-blocked by user.
   """
   def keep_following_or_not_domain_blocked(query, user) do
     where(
       query,
-      [_, activity],
+      [_, user_actor: user_actor],
       fragment(
         # "(actor's domain NOT in domain_blocks) OR (actor IS in followed AP IDs)"
         """
@@ -255,9 +255,9 @@ defmodule Pleroma.FollowingRelationship do
           ? = ANY(SELECT ap_id FROM users AS u INNER JOIN following_relationships AS fr
             ON u.id = fr.following_id WHERE fr.follower_id = ? AND fr.state = ?)
         """,
-        activity.actor,
+        user_actor.ap_id,
         ^user.domain_blocks,
-        activity.actor,
+        user_actor.ap_id,
         ^User.binary_id(user.id),
         ^accept_state_code()
       )
diff --git a/lib/pleroma/notification.ex b/lib/pleroma/notification.ex
index 368e609d2..710b19866 100644
--- a/lib/pleroma/notification.ex
+++ b/lib/pleroma/notification.ex
@@ -137,7 +137,7 @@ defmodule Pleroma.Notification do
     blocked_ap_ids = opts[:blocked_users_ap_ids] || User.blocked_users_ap_ids(user)
 
     query
-    |> where([n, a], a.actor not in ^blocked_ap_ids)
+    |> where([..., user_actor: user_actor], user_actor.ap_id not in ^blocked_ap_ids)
     |> FollowingRelationship.keep_following_or_not_domain_blocked(user)
   end
 
@@ -148,7 +148,7 @@ defmodule Pleroma.Notification do
       blocker_ap_ids = User.incoming_relationships_ungrouped_ap_ids(user, [:block])
 
       query
-      |> where([n, a], a.actor not in ^blocker_ap_ids)
+      |> where([..., user_actor: user_actor], user_actor.ap_id not in ^blocker_ap_ids)
     end
   end
 
@@ -161,7 +161,7 @@ defmodule Pleroma.Notification do
       opts[:notification_muted_users_ap_ids] || User.notification_muted_users_ap_ids(user)
 
     query
-    |> where([n, a], a.actor not in ^notification_muted_ap_ids)
+    |> where([..., user_actor: user_actor], user_actor.ap_id not in ^notification_muted_ap_ids)
     |> join(:left, [n, a], tm in ThreadMute,
       on: tm.user_id == ^user.id and tm.context == fragment("?->>'context'", a.data),
       as: :thread_mute