diff --git a/lib/ash/type/atom.ex b/lib/ash/type/atom.ex
index 88fac4c7..90666df3 100644
--- a/lib/ash/type/atom.ex
+++ b/lib/ash/type/atom.ex
@@ -49,6 +49,8 @@ defmodule Ash.Type.Atom do
     {:ok, value}
   end
 
+  def cast_input(value, ""), do: nil
+
   def cast_input(value, _) when is_binary(value) do
     {:ok, String.to_existing_atom(value)}
   rescue