diff --git a/test/map_field_type_expr_test.exs b/test/map_field_type_expr_test.exs
new file mode 100644
index 00000000..41d08a92
--- /dev/null
+++ b/test/map_field_type_expr_test.exs
@@ -0,0 +1,57 @@
+# SPDX-FileCopyrightText: 2019 ash_postgres contributors <https://github.com/ash-project/ash_postgres/graphs/contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule AshPostgres.MapFieldTypeExprTest do
+  @moduledoc false
+  use AshPostgres.RepoCase, async: false
+
+  alias AshPostgres.Test.Post
+
+  require Ash.Query
+  import Ash.Expr
+
+  setup do
+    post =
+      Post
+      |> Ash.Changeset.for_create(:create, %{
+        title: "a",
+        keyword_map: [display_template: "{{foo}}", size: 3]
+      })
+      |> Ash.create!()
+
+    %{post: post}
+  end
+
+  test "a field declared an integer is compared as an integer", %{post: post} do
+    assert [found] =
+             Post
+             |> Ash.Query.filter(keyword_map[:size] == 3)
+             |> Ash.read!()
+
+    assert found.id == post.id
+  end
+
+  test "a field declared an integer orders numerically" do
+    Post
+    |> Ash.Changeset.for_create(:create, %{
+      title: "b",
+      keyword_map: [display_template: "{{bar}}", size: 10]
+    })
+    |> Ash.create!()
+
+    assert [%{keyword_map: [display_template: "{{bar}}", size: 10]}] =
+             Post
+             |> Ash.Query.filter(keyword_map[:size] > 9)
+             |> Ash.read!()
+  end
+
+  test "a field declared a string still compares as a string", %{post: post} do
+    assert [found] =
+             Post
+             |> Ash.Query.filter(keyword_map[:display_template] == "{{foo}}")
+             |> Ash.read!()
+
+    assert found.id == post.id
+  end
+end
diff --git a/test/support/resources/post.ex b/test/support/resources/post.ex
index 33ef03a8..49f52cc3 100644
--- a/test/support/resources/post.ex
+++ b/test/support/resources/post.ex
@@ -657,6 +657,9 @@ defmodule AshPostgres.Test.Post do
         fields: [
           display_template: [
             type: :string
+          ],
+          size: [
+            type: :integer
           ]
         ]
       )