diff --git a/config/config.exs b/config/config.exs
index 589bc42..3ad0083 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -15,6 +15,7 @@ config :stripe_mock, StripeMockWeb.Endpoint,
   render_errors: [view: StripeMockWeb.ErrorView, accepts: ~w(json)]
 
 config :stripe_mock, ecto_repos: [StripeMock.Repo]
+config :stripe_mock, StripeMock.Repo, migration_primary_key: [type: :binary_id]
 
 # Configures Elixir's Logger
 config :logger, :console,
diff --git a/lib/stripe_mock/api/card.ex b/lib/stripe_mock/api/card.ex
index 8359837..54e76df 100644
--- a/lib/stripe_mock/api/card.ex
+++ b/lib/stripe_mock/api/card.ex
@@ -4,7 +4,6 @@ defmodule StripeMock.API.Card do
   schema "cards" do
     field :brand, :string
     field :deleted, :boolean
-    field :metadata, :map, default: %{}
     field :last4, :string
     field :source, :string
 
@@ -15,6 +14,7 @@ defmodule StripeMock.API.Card do
 
     belongs_to :customer, API.Customer
 
+    common_fields()
     timestamps()
   end
 
@@ -23,6 +23,7 @@ defmodule StripeMock.API.Card do
     card
     |> cast(attrs, [:source, :metadata])
     |> validate_required([:source, :metadata])
+    |> put_common_fields()
   end
 
   @doc false
@@ -39,6 +40,7 @@ defmodule StripeMock.API.Card do
     |> validate_required([:number, :exp_month, :exp_year, :cvc])
     |> set_brand()
     |> set_last4()
+    |> put_common_fields()
   end
 
   defp set_brand(changeset) do
diff --git a/lib/stripe_mock/api/charge.ex b/lib/stripe_mock/api/charge.ex
index da78851..f727fb9 100644
--- a/lib/stripe_mock/api/charge.ex
+++ b/lib/stripe_mock/api/charge.ex
@@ -53,6 +53,7 @@ defmodule StripeMock.API.Charge do
   def capture_changeset(charge, payment_intent) do
     charge
     |> change(%{payment_intent_id: payment_intent.id})
+    |> put_common_fields()
   end
 
   defp set_customer_and_source(changeset) do
diff --git a/lib/stripe_mock/api/customer.ex b/lib/stripe_mock/api/customer.ex
index c57d655..97ae798 100644
--- a/lib/stripe_mock/api/customer.ex
+++ b/lib/stripe_mock/api/customer.ex
@@ -4,12 +4,11 @@ defmodule StripeMock.API.Customer do
   schema "customers" do
     field :currency, :string, default: "usd"
     field :deleted, :boolean, default: false
-    field :description, :string
     field :email, :string
-    field :metadata, :map, default: %{}
     field :name, :string
     field :phone, :string
 
+    common_fields()
     timestamps()
   end
 
@@ -18,6 +17,7 @@ defmodule StripeMock.API.Customer do
     customer
     |> cast(attrs, [:created, :currency, :description, :email, :name, :phone])
     |> validate_email()
+    |> put_common_fields()
   end
 
   defp validate_email(changeset) do
diff --git a/lib/stripe_mock/api/refund.ex b/lib/stripe_mock/api/refund.ex
index 5ff58bf..1780d96 100644
--- a/lib/stripe_mock/api/refund.ex
+++ b/lib/stripe_mock/api/refund.ex
@@ -4,11 +4,11 @@ defmodule StripeMock.API.Refund do
 
   schema "refunds" do
     field :amount, :integer
-    field :metadata, :map, default: %{}
     field :reason, :string
 
     belongs_to :charge, API.Charge
 
+    common_fields()
     timestamps()
   end
 
@@ -21,6 +21,7 @@ defmodule StripeMock.API.Refund do
     |> validate_required(:amount)
     |> validate_amount()
     |> validate_reason()
+    |> put_common_fields()
   end
 
   @doc false
diff --git a/lib/stripe_mock/api/source.ex b/lib/stripe_mock/api/source.ex
index dffbd2d..31ca88c 100644
--- a/lib/stripe_mock/api/source.ex
+++ b/lib/stripe_mock/api/source.ex
@@ -4,11 +4,14 @@ defmodule StripeMock.API.Source do
   schema "sources" do
     belongs_to :card, API.Card
     belongs_to :token, API.Card
+    common_fields()
+    timestamps()
   end
 
   @doc false
   def changeset(token, attrs) do
     token
     |> cast(attrs, [:card_id, :token_id])
+    |> put_common_fields()
   end
 end
diff --git a/lib/stripe_mock/api/token.ex b/lib/stripe_mock/api/token.ex
index a3cced2..ee147a2 100644
--- a/lib/stripe_mock/api/token.ex
+++ b/lib/stripe_mock/api/token.ex
@@ -8,6 +8,7 @@ defmodule StripeMock.API.Token do
 
     belongs_to :card, API.Card
 
+    common_fields()
     timestamps()
   end
 
@@ -18,6 +19,7 @@ defmodule StripeMock.API.Token do
     |> cast_assoc(:card, with: &API.Card.token_changeset/2)
     |> set_type()
     |> validate_required([:type])
+    |> put_common_fields()
   end
 
   defp set_type(changeset) do
diff --git a/lib/stripe_mock/id.ex b/lib/stripe_mock/id.ex
index 84f6e4e..1cda74a 100644
--- a/lib/stripe_mock/id.ex
+++ b/lib/stripe_mock/id.ex
@@ -2,11 +2,42 @@ defmodule StripeMock.ID do
   @moduledoc """
   Generates a somewhat Stripe-esque random ID string. Pretty much a base52-encoded UUID.
   """
+  alias StripeMock.API
 
+  @spec generate() :: String.t()
   def generate() do
-    :crypto.strong_rand_bytes(16)
+    from_bytes(:crypto.strong_rand_bytes(16))
+  end
+
+  @spec from_uuid(String.t()) :: String.t() | none()
+  def from_uuid(uuid) do
+    {:ok, bytes} = Ecto.UUID.dump(uuid)
+    from_bytes(bytes)
+  end
+
+  defp from_bytes(bytes) do
+    bytes
     |> :erlang.binary_to_list()
-    |> Enum.reduce(1, &(&1 * &2))
+    |> Enum.reduce(1, &if(&1 > 0, do: &1 * &2, else: &2))
     |> StripeMock.Base52.encode()
   end
+
+  @spec type(module()) :: atom()
+  def type(%{} = map), do: type(map.__struct__)
+  def type(API.Card), do: :card
+  def type(API.Charge), do: :charge
+  def type(API.Customer), do: :customer
+  def type(API.PaymentMethod), do: :payment_method
+  def type(API.PaymentIntent), do: :payment_intent
+  def type(API.Refund), do: :refund
+  def type(API.Token), do: :token
+
+  @spec type(map()) :: String.t()
+  def prefix(%API.Card{}), do: "card"
+  def prefix(%API.Charge{}), do: "ch"
+  def prefix(%API.Customer{}), do: "cus"
+  def prefix(%API.PaymentMethod{}), do: "pm"
+  def prefix(%API.PaymentIntent{}), do: "pi"
+  def prefix(%API.Refund{}), do: "re"
+  def prefix(%API.Token{}), do: "tok"
 end
diff --git a/lib/stripe_mock/migrator.ex b/lib/stripe_mock/migrator.ex
index 52bb8f7..8bad7a6 100644
--- a/lib/stripe_mock/migrator.ex
+++ b/lib/stripe_mock/migrator.ex
@@ -36,12 +36,7 @@ defmodule StripeMock.Migrator do
     IO.puts("Starting dependencies")
     Enum.each(@start_apps, &Application.ensure_all_started/1)
 
-    Application.load(:basic_space)
-
-    # Start the Repo(s) for app
-    # Switch pool_size to 2 for ecto > 3.0
-    IO.puts("Starting repos")
-    Enum.each(@repos, & &1.start_link(pool_size: 2))
+    Application.load(:stripe_mock)
 
     # Run migrations
     Enum.each(@repos, &run_migrations_for/1)
diff --git a/lib/stripe_mock/repo.ex b/lib/stripe_mock/repo.ex
index 3a3e264..7f8b593 100644
--- a/lib/stripe_mock/repo.ex
+++ b/lib/stripe_mock/repo.ex
@@ -4,7 +4,7 @@ defmodule StripeMock.Repo do
   alias StripeMock.API
 
   @impl true
-  def init(_type, config) do
+  def init(:supervisor, config) do
     {uri, _} = System.cmd("pg_tmp", ["-t"])
 
     [[username, host, port, database]] =
@@ -24,16 +24,23 @@ defmodule StripeMock.Repo do
     {:ok, config}
   end
 
+  def init(_type, config) do
+    {:ok, config}
+  end
+
   def fetch(schema, id) do
-    with true <- valid_id?(id),
-         %{} = object <- get(schema, id) do
-      {:ok, object}
+    if valid_uuid?(id) do
+      get(schema, id)
     else
-      _ -> {:error, :not_found}
+      get_by(schema, stripe_id: id)
+    end
+    |> case do
+      nil -> {:error, :not_found}
+      object -> {:ok, object}
     end
   end
 
-  defp valid_id?(id) do
+  defp valid_uuid?(id) do
     case Ecto.UUID.cast(id) do
       {:ok, _} -> true
       _ -> false
@@ -61,23 +68,4 @@ defmodule StripeMock.Repo do
       changeset
     end
   end
-
-  defp generate_id(schema) do
-    prefix(schema) <> "_" <> StripeMock.ID.generate()
-  end
-
-  def type(%{} = map), do: type(map.__struct__)
-  def type(API.Card), do: :card
-  def type(API.Charge), do: :charge
-  def type(API.Customer), do: :customer
-  def type(API.PaymentIntent), do: :payment_intent
-  def type(API.Refund), do: :refund
-  def type(API.Token), do: :token
-
-  def prefix(%API.Card{}), do: "card"
-  def prefix(%API.Charge{}), do: "ch"
-  def prefix(%API.Customer{}), do: "cus"
-  def prefix(%API.PaymentIntent{}), do: "pi"
-  def prefix(%API.Refund{}), do: "re"
-  def prefix(%API.Token{}), do: "tok"
 end
diff --git a/lib/stripe_mock/schema.ex b/lib/stripe_mock/schema.ex
index 688b7e0..9160edc 100644
--- a/lib/stripe_mock/schema.ex
+++ b/lib/stripe_mock/schema.ex
@@ -1,4 +1,7 @@
 defmodule StripeMock.Schema do
+  import Ecto.Changeset
+  alias StripeMock.ID
+
   defmacro __using__(_) do
     quote do
       use Ecto.Schema
@@ -7,7 +10,7 @@ defmodule StripeMock.Schema do
       import unquote(__MODULE__)
       alias StripeMock.{API, Repo}
 
-      Module.put_attribute(__MODULE__, :primary_key, {:id, :binary_id, autogenerate: true})
+      Module.put_attribute(__MODULE__, :primary_key, {:id, :binary_id, autogenerate: false})
       Module.put_attribute(__MODULE__, :foreign_key_type, :binary_id)
       Module.put_attribute(__MODULE__, :timestamps_opts, inserted_at: :created, updated_at: false)
     end
@@ -15,14 +18,34 @@ defmodule StripeMock.Schema do
 
   defmacro common_fields() do
     quote do
+      field :stripe_id, :string
       field :description, :string
       field :metadata, :map, default: %{}
     end
   end
 
-  import Ecto.Changeset
-
   def put_common_fields(changeset) do
-    validate_required(changeset, [:metadata])
+    changeset
+    |> validate_required(required_fields(changeset))
+    |> put_ids()
+  end
+
+  defp required_fields(changeset) do
+    Enum.filter([:metadata], &Map.has_key?(changeset.data, &1))
+  end
+
+  defp put_ids(changeset) do
+    case get_field(changeset, :id) do
+      nil -> do_put_stripe_id(changeset)
+      _ -> changeset
+    end
+  end
+
+  defp do_put_stripe_id(changeset) do
+    uuid = Ecto.UUID.generate()
+    prefix = ID.prefix(changeset.data)
+    stripe_id = prefix <> "_" <> StripeMock.ID.from_uuid(uuid)
+
+    change(changeset, %{id: uuid, stripe_id: stripe_id})
   end
 end
diff --git a/lib/stripe_mock_web/view_helpers.ex b/lib/stripe_mock_web/view_helpers.ex
index 236c4d5..f15a4bc 100644
--- a/lib/stripe_mock_web/view_helpers.ex
+++ b/lib/stripe_mock_web/view_helpers.ex
@@ -1,9 +1,14 @@
 defmodule StripeMockWeb.ViewHelpers do
-  def as_map(struct) do
-    struct
+  def as_map(struct, object \\ nil) do
+    if is_bitstring(object) do
+      Map.put(struct, :object, object)
+    else
+      struct
+    end
     |> update_created()
     |> Map.delete(:__struct__)
     |> Map.delete(:__meta__)
+    |> Map.put(:id, struct.stripe_id)
   end
 
   defp update_created(%{created: %{} = timestamp} = struct) do
diff --git a/lib/stripe_mock_web/views/card_view.ex b/lib/stripe_mock_web/views/card_view.ex
index dfcfe01..940cb3f 100644
--- a/lib/stripe_mock_web/views/card_view.ex
+++ b/lib/stripe_mock_web/views/card_view.ex
@@ -12,10 +12,9 @@ defmodule StripeMockWeb.CardView do
 
   def render("card.json", %{card: card}) do
     card
-    |> Map.take(~w(id created deleted exp_month exp_year metadata last4 brand)a)
-    |> Map.put("object", "card")
+    |> as_map("card")
+    |> Map.take(~w(id object created deleted exp_month exp_year metadata last4 brand)a)
     |> Map.put("customer", card.customer_id)
-    |> as_map()
   end
 
   def render("delete.json", %{card: card}) do
diff --git a/lib/stripe_mock_web/views/charge_view.ex b/lib/stripe_mock_web/views/charge_view.ex
index 705ce20..1905de1 100644
--- a/lib/stripe_mock_web/views/charge_view.ex
+++ b/lib/stripe_mock_web/views/charge_view.ex
@@ -11,21 +11,16 @@ defmodule StripeMockWeb.ChargeView do
   end
 
   def render("charge.json", %{charge: charge}) do
-    %{
-      id: charge.id,
-      amount: charge.amount,
-      currency: charge.currency,
-      capture: charge.capture,
+    charge
+    |> as_map("charge")
+    |> Map.take(
+      ~w(id object amount currency capture description metadata statement_descriptor transfer_group)a
+    )
+    |> Map.merge(%{
       customer: charge.customer_id,
-      description: charge.description,
-      metadata: charge.metadata,
-      object: "charge",
       outcome: render_outcome(charge),
-      payment_method: render(StripeMockWeb.CardView, "card.json", card: charge.card),
-      statement_descriptor: charge.statement_descriptor,
-      transfer_group: charge.transfer_group
-    }
-    |> as_map()
+      payment_method: render(StripeMockWeb.CardView, "card.json", card: charge.card)
+    })
   end
 
   defp render_outcome(_charge) do
diff --git a/lib/stripe_mock_web/views/customer_view.ex b/lib/stripe_mock_web/views/customer_view.ex
index a155246..781d163 100644
--- a/lib/stripe_mock_web/views/customer_view.ex
+++ b/lib/stripe_mock_web/views/customer_view.ex
@@ -15,7 +15,7 @@ defmodule StripeMockWeb.CustomerView do
     sources = API.list_cards(customer) |> Pagination.paginate()
 
     customer
-    |> as_map()
+    |> as_map("customer")
     |> Map.put(:sources, render_page(conn, sources, CardView, "card.json"))
   end
 end
diff --git a/lib/stripe_mock_web/views/payment_intent_view.ex b/lib/stripe_mock_web/views/payment_intent_view.ex
index eaa599f..11e1be3 100644
--- a/lib/stripe_mock_web/views/payment_intent_view.ex
+++ b/lib/stripe_mock_web/views/payment_intent_view.ex
@@ -12,9 +12,9 @@ defmodule StripeMockWeb.PaymentIntentView do
 
   def render("payment_intent.json", %{payment_intent: payment_intent}) do
     payment_intent
-    |> as_map()
+    |> as_map("payment_intent")
     |> Map.take(
-      ~w(amount capture_method confirmation_method currency description id metadata payment_method_types statement_descriptor status transfer_group)a
+      ~w(id object amount capture_method confirmation_method currency description metadata payment_method_types statement_descriptor status transfer_group)a
     )
     |> Map.put("customer", payment_intent.customer_id)
     |> Map.merge(%{
diff --git a/lib/stripe_mock_web/views/payment_method_view.ex b/lib/stripe_mock_web/views/payment_method_view.ex
index 1461900..82713df 100644
--- a/lib/stripe_mock_web/views/payment_method_view.ex
+++ b/lib/stripe_mock_web/views/payment_method_view.ex
@@ -15,8 +15,8 @@ defmodule StripeMockWeb.PaymentMethodView do
     payment_object = render(StripeMockWeb.CardView, "card.json", card: card)
 
     payment_method
-    |> Map.take(~w(id created description metadata)a)
-    |> as_map()
+    |> as_map("payment_method")
+    |> Map.take(~w(id object created description metadata)a)
     |> Map.put(:card, payment_object)
   end
 
diff --git a/lib/stripe_mock_web/views/refund_view.ex b/lib/stripe_mock_web/views/refund_view.ex
index 0540f29..79e989b 100644
--- a/lib/stripe_mock_web/views/refund_view.ex
+++ b/lib/stripe_mock_web/views/refund_view.ex
@@ -12,7 +12,8 @@ defmodule StripeMockWeb.RefundView do
 
   def render("refund.json", %{refund: refund}) do
     refund
-    |> Map.take(~w(id created amount metadata reason)a)
+    |> as_map("refund")
+    |> Map.take(~w(id object created amount metadata reason)a)
     |> Map.put(:charge, refund.charge_id)
   end
 end
diff --git a/lib/stripe_mock_web/views/token_view.ex b/lib/stripe_mock_web/views/token_view.ex
index 24cf890..0f86c0b 100644
--- a/lib/stripe_mock_web/views/token_view.ex
+++ b/lib/stripe_mock_web/views/token_view.ex
@@ -11,21 +11,16 @@ defmodule StripeMockWeb.TokenView do
   end
 
   def render("token.json", %{token: token}) do
-    object = %{
-      id: token.id,
-      object: "token",
-      client_ip: token.client_ip,
-      created: token.created,
-      type: token.type,
-      used: token.used
-    }
+    token
+    |> as_map("token")
+    |> Map.take(~w(id object card client_ip created type used)a)
+    |> case do
+      %{card: %API.Card{}} = token ->
+        card = render(CardView, "card.json", card: token.card)
+        %{token | card: card}
 
-    if token.card do
-      card = render(CardView, "card.json", card: token.card)
-      Map.put(object, :card, card)
-    else
-      object
+      token ->
+        token
     end
-    |> as_map()
   end
 end
diff --git a/priv/repo/migrations/20191015221147_create_tables.exs b/priv/repo/migrations/20191015221147_create_tables.exs
index f936e0f..1b7297a 100644
--- a/priv/repo/migrations/20191015221147_create_tables.exs
+++ b/priv/repo/migrations/20191015221147_create_tables.exs
@@ -3,6 +3,7 @@ defmodule StripeMock.Repo.Migrations.CreateTables do
 
   defmacro common_fields() do
     quote do
+      add(:stripe_id, :string, null: false)
       add(:deleted, :boolean, null: false, default: false)
       add(:description, :string, null: true)
       add(:metadata, :map, null: false, default: %{})
diff --git a/test/stripe_mock_web/controllers/charge_controller_test.exs b/test/stripe_mock_web/controllers/charge_controller_test.exs
index 900e0de..0a1e445 100644
--- a/test/stripe_mock_web/controllers/charge_controller_test.exs
+++ b/test/stripe_mock_web/controllers/charge_controller_test.exs
@@ -2,8 +2,6 @@ defmodule StripeMockWeb.ChargeControllerTest do
   use StripeMockWeb.ConnCase
   @moduletag :charge
 
-  alias StripeMock.API.Charge
-
   setup :create_customer
   setup :create_card
 
@@ -32,7 +30,7 @@ defmodule StripeMockWeb.ChargeControllerTest do
       conn = get(conn, Routes.charge_path(conn, :show, id))
 
       assert %{
-               "id" => id,
+               "id" => "ch_" <> id,
                "amount" => 5000,
                "capture" => true,
                "currency" => "some currency",
@@ -76,9 +74,9 @@ defmodule StripeMockWeb.ChargeControllerTest do
   describe "update charge" do
     setup [:create_charge]
 
-    test "renders charge when data is valid", %{conn: conn, charge: %Charge{id: id} = charge} do
+    test "renders charge when data is valid", %{conn: conn, charge: charge} do
       conn = put(conn, Routes.charge_path(conn, :update, charge), update_attrs())
-      assert %{"id" => ^id} = json_response(conn, 200)
+      assert %{"id" => "ch_" <> _ = id} = json_response(conn, 200)
 
       conn = get(conn, Routes.charge_path(conn, :show, id))
 
diff --git a/test/stripe_mock_web/controllers/customer_controller_test.exs b/test/stripe_mock_web/controllers/customer_controller_test.exs
index e592bb4..ad72dae 100644
--- a/test/stripe_mock_web/controllers/customer_controller_test.exs
+++ b/test/stripe_mock_web/controllers/customer_controller_test.exs
@@ -29,7 +29,7 @@ defmodule StripeMockWeb.CustomerControllerTest do
 
     test "renders customer data", %{conn: conn, customer: customer} do
       conn = get(conn, Routes.customer_path(conn, :show, customer.id))
-      assert %{"id" => id} = json_response(conn, 200)
+      assert %{"id" => "cus_" <> id} = json_response(conn, 200)
     end
 
     test "renders 404 on not found", %{conn: conn} do
@@ -45,7 +45,7 @@ defmodule StripeMockWeb.CustomerControllerTest do
 
       conn = get(conn, Routes.customer_path(conn, :show, id))
 
-      assert %{"id" => id} = json_response(conn, 200)
+      assert %{"id" => "cus_" <> id} = json_response(conn, 200)
     end
 
     test "renders errors when data is invalid", %{conn: conn} do
@@ -57,16 +57,13 @@ defmodule StripeMockWeb.CustomerControllerTest do
   describe "update customer" do
     setup [:create_customer]
 
-    test "renders customer when data is valid", %{
-      conn: conn,
-      customer: %Customer{id: id} = customer
-    } do
+    test "renders customer when data is valid", %{conn: conn, customer: customer} do
       conn = put(conn, Routes.customer_path(conn, :update, customer), @update_attrs)
-      assert %{"id" => ^id} = json_response(conn, 200)
+      assert %{"id" => "cus_" <> _ = id} = json_response(conn, 200)
 
       conn = get(conn, Routes.customer_path(conn, :show, id))
 
-      assert %{"id" => id} = json_response(conn, 200)
+      assert %{"id" => "cus_" <> _} = json_response(conn, 200)
     end
 
     test "renders errors when data is invalid", %{conn: conn, customer: customer} do
diff --git a/test/stripe_mock_web/controllers/payment_intent_controller_test.exs b/test/stripe_mock_web/controllers/payment_intent_controller_test.exs
index 38a271e..8e9e53f 100644
--- a/test/stripe_mock_web/controllers/payment_intent_controller_test.exs
+++ b/test/stripe_mock_web/controllers/payment_intent_controller_test.exs
@@ -2,8 +2,6 @@ defmodule StripeMockWeb.PaymentIntentControllerTest do
   use StripeMockWeb.ConnCase
   @moduletag :payment_intent
 
-  alias StripeMock.API.PaymentIntent
-
   setup :create_customer
   setup :create_card
 
@@ -78,9 +76,8 @@ defmodule StripeMockWeb.PaymentIntentControllerTest do
       conn: conn,
       payment_intent: payment_intent
     } do
-      %PaymentIntent{id: id} = payment_intent
       conn = put(conn, Routes.payment_intent_path(conn, :update, payment_intent), update_attrs())
-      assert %{"id" => ^id} = json_response(conn, 200)
+      assert %{"id" => "pi_" <> _ = id} = json_response(conn, 200)
 
       conn = get(conn, Routes.payment_intent_path(conn, :show, id))
 
diff --git a/test/stripe_mock_web/controllers/refund_controller_test.exs b/test/stripe_mock_web/controllers/refund_controller_test.exs
index d29daf0..b9dfe28 100644
--- a/test/stripe_mock_web/controllers/refund_controller_test.exs
+++ b/test/stripe_mock_web/controllers/refund_controller_test.exs
@@ -2,8 +2,6 @@ defmodule StripeMockWeb.RefundControllerTest do
   use StripeMockWeb.ConnCase
   @moduletag :refund
 
-  alias StripeMock.API.Refund
-
   setup :create_customer
   setup :create_charge
 
@@ -71,11 +69,11 @@ defmodule StripeMockWeb.RefundControllerTest do
   describe "update refund" do
     setup [:create_refund]
 
-    test "renders refund when data is valid", %{conn: conn, refund: %Refund{id: id} = refund} do
+    test "renders refund when data is valid", %{conn: conn, refund: refund} do
       assert refund.metadata == %{}
 
       conn = put(conn, Routes.refund_path(conn, :update, refund), %{metadata: %{"key" => "val"}})
-      assert %{"id" => ^id} = json_response(conn, 200)
+      assert %{"id" => "re_" <> _ = id} = json_response(conn, 200)
 
       conn = get(conn, Routes.refund_path(conn, :show, id))
 
diff --git a/test/stripe_mock_web/controllers/source_controller_test.exs b/test/stripe_mock_web/controllers/source_controller_test.exs
index 8cd8a0f..45b5553 100644
--- a/test/stripe_mock_web/controllers/source_controller_test.exs
+++ b/test/stripe_mock_web/controllers/source_controller_test.exs
@@ -2,7 +2,6 @@ defmodule StripeMockWeb.SourceControllerTest do
   use StripeMockWeb.ConnCase
   @moduletag :source
 
-  alias StripeMock.API.Card
   alias StripeMock.CardFixture
 
   @card_attrs CardFixture.valid_card()
@@ -56,13 +55,13 @@ defmodule StripeMockWeb.SourceControllerTest do
   describe "update card" do
     setup [:create_card]
 
-    test "renders card when data is valid", %{conn: conn, card: %Card{id: id} = card} do
+    test "renders card when data is valid", %{conn: conn, card: card} do
       conn =
         put(conn, Routes.customer_source_path(conn, :update, card.customer_id, card),
           card: @update_attrs
         )
 
-      assert %{"id" => ^id, "object" => "card"} = json_response(conn, 200)
+      assert %{"id" => "card_" <> _ = id, "object" => "card"} = json_response(conn, 200)
 
       conn = get(conn, Routes.customer_source_path(conn, :show, card.customer_id, card))
 
@@ -91,7 +90,7 @@ defmodule StripeMockWeb.SourceControllerTest do
         |> get(Routes.customer_source_path(conn, :index, card.customer_id, object: "card"))
         |> json_response(200)
 
-      assert Enum.find(data, &(&1["id"] == card.id))
+      assert Enum.find(data, &(&1["id"] == card.stripe_id))
 
       delete(conn, Routes.customer_source_path(conn, :delete, card.customer_id, card))
 
@@ -100,7 +99,7 @@ defmodule StripeMockWeb.SourceControllerTest do
         |> get(Routes.customer_source_path(conn, :index, card.customer_id, object: "card"))
         |> json_response(200)
 
-      refute Enum.find(data, &(&1["id"] == card.id))
+      refute Enum.find(data, &(&1["id"] == card.stripe_id))
     end
   end
 end