diff --git a/lib/pleroma/web/api_spec/cast_and_validate.ex b/lib/pleroma/web/api_spec/cast_and_validate.ex
index bd9026237..fbfc27d6f 100644
--- a/lib/pleroma/web/api_spec/cast_and_validate.ex
+++ b/lib/pleroma/web/api_spec/cast_and_validate.ex
@@ -40,7 +40,7 @@ def call(%{private: %{open_api_spex: private_data}} = conn, %{
           |> List.first()
 
         _ ->
-          nil
+          "application/json"
       end
 
     private_data = Map.put(private_data, :operation_id, operation_id)
diff --git a/test/web/mastodon_api/controllers/account_controller_test.exs b/test/web/mastodon_api/controllers/account_controller_test.exs
index ebfcedd01..260ad2306 100644
--- a/test/web/mastodon_api/controllers/account_controller_test.exs
+++ b/test/web/mastodon_api/controllers/account_controller_test.exs
@@ -780,7 +780,6 @@ test "with notifications", %{conn: conn} do
 
       assert %{"id" => _id, "muting" => true, "muting_notifications" => true} =
                conn
-               |> put_req_header("content-type", "application/json")
                |> post("/api/v1/accounts/#{other_user.id}/mute")
                |> json_response_and_validate_schema(200)