diff --git a/lib/ash/type/atom.ex b/lib/ash/type/atom.ex
index aecdc3d8..31b3422d 100644
--- a/lib/ash/type/atom.ex
+++ b/lib/ash/type/atom.ex
@@ -49,7 +49,7 @@ defmodule Ash.Type.Atom do
     {:ok, value}
   end
 
-  def cast_input(_value, ""), do: nil
+  def cast_input("", _), do: nil
 
   def cast_input(value, _) when is_binary(value) do
     {:ok, String.to_existing_atom(value)}