diff --git a/lib/philomena_web/controllers/activity_controller.ex b/lib/philomena_web/controllers/activity_controller.ex
index 252d31c2..6cc3ddf6 100644
--- a/lib/philomena_web/controllers/activity_controller.ex
+++ b/lib/philomena_web/controllers/activity_controller.ex
@@ -23,7 +23,7 @@ defmodule PhilomenaWeb.ActivityController do
     {:ok, {images, _tags}} =
       ImageLoader.search_string(
         conn,
-        "created_at.lte:3 minutes ago, thumbnails_generated:true",
+        "created_at.lte:3 minutes ago, -thumbnails_generated:false",
         pagination: %{conn.assigns.image_pagination | page_number: 1}
       )
 
diff --git a/lib/philomena_web/controllers/image_controller.ex b/lib/philomena_web/controllers/image_controller.ex
index 83c87786..95b10dd9 100644
--- a/lib/philomena_web/controllers/image_controller.ex
+++ b/lib/philomena_web/controllers/image_controller.ex
@@ -37,7 +37,7 @@ defmodule PhilomenaWeb.ImageController do
 
   def index(conn, _params) do
     {:ok, {images, _tags}} =
-      ImageLoader.search_string(conn, "created_at.lte:3 minutes ago, thumbnails_generated:true")
+      ImageLoader.search_string(conn, "created_at.lte:3 minutes ago, -thumbnails_generated:false")
 
     images = Elasticsearch.search_records(images, preload(Image, tags: :aliases))