diff --git a/lib/elixir/lib/module/types/descr.ex b/lib/elixir/lib/module/types/descr.ex
index cee9c6fefcc..e7cf7bc9cf3 100644
--- a/lib/elixir/lib/module/types/descr.ex
+++ b/lib/elixir/lib/module/types/descr.ex
@@ -407,6 +407,11 @@ defmodule Module.Types.Descr do
   defp pop_dynamic(:term), do: {:term, :term}
   defp pop_dynamic(descr), do: Map.pop(descr, :dynamic, descr)
 
+  defp put_dynamic(:term, dynamic), do: optional_to_term(%{dynamic: dynamic})
+  defp put_dynamic(static, dynamic) when static == dynamic, do: static
+  defp put_dynamic(_static, dynamic) when dynamic == @none, do: @none
+  defp put_dynamic(static, dynamic), do: Map.put(static, :dynamic, dynamic)
+
   @doc """
   Computes the union of two descrs.
   """
@@ -502,7 +507,8 @@ defmodule Module.Types.Descr do
       {right_dynamic, right_static} = pop_dynamic(right)
       dynamic_part = bare_difference_static(left_dynamic, right_static)
 
-      Map.put(bare_difference_static(left_static, right_dynamic), :dynamic, dynamic_part)
+      bare_difference_static(left_static, right_dynamic)
+      |> put_dynamic(dynamic_part)
     else
       bare_difference_static(left, right)
     end
@@ -6125,7 +6131,8 @@ defmodule Module.Types.Descr do
       {right_dynamic, right_static} = pop_dynamic(right)
       dynamic_part = opt_difference_static(left_dynamic, right_static)
 
-      Map.put(opt_difference_static(left_static, right_dynamic), :dynamic, dynamic_part)
+      opt_difference_static(left_static, right_dynamic)
+      |> put_dynamic(dynamic_part)
     else
       opt_difference_static(left, right)
     end
diff --git a/lib/elixir/test/elixir/module/types/descr_test.exs b/lib/elixir/test/elixir/module/types/descr_test.exs
index b48049f2c48..84e25ac0537 100644
--- a/lib/elixir/test/elixir/module/types/descr_test.exs
+++ b/lib/elixir/test/elixir/module/types/descr_test.exs
@@ -620,7 +620,10 @@ defmodule Module.Types.DescrTest do
       assert equal?(dynamic(), opt_difference(term(), dynamic()))
       assert empty?(opt_difference(dynamic(), term()))
       assert empty?(opt_difference(none(), dynamic()))
-      assert empty?(opt_difference(dynamic(integer()), integer()))
+      assert opt_difference(dynamic(integer()), integer()) == none()
+
+      # Covers assembling a result with static :term and dynamic unfolded term.
+      assert opt_difference(term(), %{dynamic: none(), optional: 1}) == term()
     end
 
     test "tuple" do
@@ -3336,6 +3339,7 @@ defmodule Module.Types.DescrTest do
 
     test "dynamic (negation)" do
       assert dynamic(opt_negation(integer())) |> to_quoted_string() == "dynamic(not integer())"
+      assert opt_negation(dynamic(none())) == term()
 
       assert opt_negation(dynamic(integer())) |> to_quoted_string() ==
                "dynamic() or not integer()"