diff --git a/lib/diffo/type/value.ex b/lib/diffo/type/value.ex
index 43b1999..5fbcd5e 100644
--- a/lib/diffo/type/value.ex
+++ b/lib/diffo/type/value.ex
@@ -89,6 +89,12 @@ defmodule Diffo.Type.Value do
       storage: :type_and_value
     ]
 
+  def cast_input(%Diffo.Type.Dynamic{} = dynamic, constraints) do
+    super(%{type: "dynamic", value: dynamic}, constraints)
+  end
+
+  def cast_input(value, constraints), do: super(value, constraints)
+
   def handle_change(_old_value, nil, _constraints), do: {:ok, nil}
   def handle_change(old_value, new_value, constraints), do: super(old_value, new_value, constraints)
 
diff --git a/test/type/value_test.exs b/test/type/value_test.exs
index 4b311ba..6bdaf72 100644
--- a/test/type/value_test.exs
+++ b/test/type/value_test.exs
@@ -33,7 +33,6 @@ defmodule Diffo.Type.ValueTest do
                Ash.Type.cast_input(Value, value, Value.subtype_constraints())
     end
 
-    @tag :skip
     test "cast_input dynamic" do
       value = %Dynamic{type: Patch, value: %Patch{aEnd: 1, zEnd: 42}}