diff --git a/test/form_test.exs b/test/form_test.exs
index 8891043..bfeb333 100644
--- a/test/form_test.exs
+++ b/test/form_test.exs
@@ -1160,6 +1160,16 @@ defmodule AshPhoenix.FormTest do
 
       assert is_nil(Map.get(params, "author", "shouldn't exist"))
     end
+
+    test "when add_forming a required argument, the added form should be valid without needing to manually validate it" do
+      form =
+        Post
+        |> Form.for_create(:create_author_required, api: Api, forms: [auto?: true])
+        |> Form.validate(%{"text" => "foo"})
+        |> Form.add_form([:author], params: %{"email" => "james@foo.com"})
+
+      assert form.valid? == true
+    end
   end
 
   describe "issue #259" do
diff --git a/test/support/resources/post.ex b/test/support/resources/post.ex
index a52cfdb..3e5d356 100644
--- a/test/support/resources/post.ex
+++ b/test/support/resources/post.ex
@@ -25,6 +25,11 @@ defmodule AshPhoenix.Test.Post do
       change(manage_relationship(:author, type: :direct_control, on_missing: :unrelate))
     end
 
+    create :create_author_required do
+      argument(:author, :map, allow_nil?: false)
+      change(manage_relationship(:author, type: :direct_control, on_missing: :unrelate))
+    end
+
     update :update_with_replace do
       argument(:comments, {:array, :map})
       change(manage_relationship(:comments, type: :replace))