diff --git a/lib/philomena/galleries.ex b/lib/philomena/galleries.ex
index d1f54319..97bc9c39 100644
--- a/lib/philomena/galleries.ex
+++ b/lib/philomena/galleries.ex
@@ -101,4 +101,100 @@ defmodule Philomena.Galleries do
   def change_gallery(%Gallery{} = gallery) do
     Gallery.changeset(gallery, %{})
   end
+
+  alias Philomena.Galleries.Subscription
+
+  @doc """
+  Returns the list of gallery_subscriptions.
+
+  ## Examples
+
+      iex> list_gallery_subscriptions()
+      [%Subscription{}, ...]
+
+  """
+  def list_gallery_subscriptions do
+    Repo.all(Subscription)
+  end
+
+  @doc """
+  Gets a single subscription.
+
+  Raises `Ecto.NoResultsError` if the Subscription does not exist.
+
+  ## Examples
+
+      iex> get_subscription!(123)
+      %Subscription{}
+
+      iex> get_subscription!(456)
+      ** (Ecto.NoResultsError)
+
+  """
+  def get_subscription!(id), do: Repo.get!(Subscription, id)
+
+  @doc """
+  Creates a subscription.
+
+  ## Examples
+
+      iex> create_subscription(%{field: value})
+      {:ok, %Subscription{}}
+
+      iex> create_subscription(%{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def create_subscription(attrs \\ %{}) do
+    %Subscription{}
+    |> Subscription.changeset(attrs)
+    |> Repo.insert()
+  end
+
+  @doc """
+  Updates a subscription.
+
+  ## Examples
+
+      iex> update_subscription(subscription, %{field: new_value})
+      {:ok, %Subscription{}}
+
+      iex> update_subscription(subscription, %{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_subscription(%Subscription{} = subscription, attrs) do
+    subscription
+    |> Subscription.changeset(attrs)
+    |> Repo.update()
+  end
+
+  @doc """
+  Deletes a Subscription.
+
+  ## Examples
+
+      iex> delete_subscription(subscription)
+      {:ok, %Subscription{}}
+
+      iex> delete_subscription(subscription)
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def delete_subscription(%Subscription{} = subscription) do
+    Repo.delete(subscription)
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for tracking subscription changes.
+
+  ## Examples
+
+      iex> change_subscription(subscription)
+      %Ecto.Changeset{source: %Subscription{}}
+
+  """
+  def change_subscription(%Subscription{} = subscription) do
+    Subscription.changeset(subscription, %{})
+  end
 end
diff --git a/lib/philomena/galleries/interaction.ex b/lib/philomena/galleries/interaction.ex
index 5c5166ae..ce387d70 100644
--- a/lib/philomena/galleries/interaction.ex
+++ b/lib/philomena/galleries/interaction.ex
@@ -2,9 +2,11 @@ defmodule Philomena.Galleries.Interaction do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key false
+
   schema "gallery_interactions" do
-    belongs_to :gallery, Philomena.Galleries.Gallery
-    belongs_to :image, Philomena.Images.Image
+    belongs_to :gallery, Philomena.Galleries.Gallery, primary_key: true
+    belongs_to :image, Philomena.Images.Image, primary_key: true
 
     field :position, :integer
   end
diff --git a/lib/philomena/galleries/subscription.ex b/lib/philomena/galleries/subscription.ex
new file mode 100644
index 00000000..543af322
--- /dev/null
+++ b/lib/philomena/galleries/subscription.ex
@@ -0,0 +1,18 @@
+defmodule Philomena.Galleries.Subscription do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @primary_key false
+
+  schema "gallery_subscriptions" do
+    belongs_to :gallery, Philomena.Galleries.Gallery, primary_key: true
+    belongs_to :user, Philomena.Users.User, primary_key: true
+  end
+
+  @doc false
+  def changeset(subscription, attrs) do
+    subscription
+    |> cast(attrs, [])
+    |> validate_required([])
+  end
+end
diff --git a/test/philomena/galleries_test.exs b/test/philomena/galleries_test.exs
index 69de771e..74c17d73 100644
--- a/test/philomena/galleries_test.exs
+++ b/test/philomena/galleries_test.exs
@@ -59,4 +59,61 @@ defmodule Philomena.GalleriesTest do
       assert %Ecto.Changeset{} = Galleries.change_gallery(gallery)
     end
   end
+
+  describe "gallery_subscriptions" do
+    alias Philomena.Galleries.Subscription
+
+    @valid_attrs %{}
+    @update_attrs %{}
+    @invalid_attrs %{}
+
+    def subscription_fixture(attrs \\ %{}) do
+      {:ok, subscription} =
+        attrs
+        |> Enum.into(@valid_attrs)
+        |> Galleries.create_subscription()
+
+      subscription
+    end
+
+    test "list_gallery_subscriptions/0 returns all gallery_subscriptions" do
+      subscription = subscription_fixture()
+      assert Galleries.list_gallery_subscriptions() == [subscription]
+    end
+
+    test "get_subscription!/1 returns the subscription with given id" do
+      subscription = subscription_fixture()
+      assert Galleries.get_subscription!(subscription.id) == subscription
+    end
+
+    test "create_subscription/1 with valid data creates a subscription" do
+      assert {:ok, %Subscription{} = subscription} = Galleries.create_subscription(@valid_attrs)
+    end
+
+    test "create_subscription/1 with invalid data returns error changeset" do
+      assert {:error, %Ecto.Changeset{}} = Galleries.create_subscription(@invalid_attrs)
+    end
+
+    test "update_subscription/2 with valid data updates the subscription" do
+      subscription = subscription_fixture()
+      assert {:ok, %Subscription{} = subscription} = Galleries.update_subscription(subscription, @update_attrs)
+    end
+
+    test "update_subscription/2 with invalid data returns error changeset" do
+      subscription = subscription_fixture()
+      assert {:error, %Ecto.Changeset{}} = Galleries.update_subscription(subscription, @invalid_attrs)
+      assert subscription == Galleries.get_subscription!(subscription.id)
+    end
+
+    test "delete_subscription/1 deletes the subscription" do
+      subscription = subscription_fixture()
+      assert {:ok, %Subscription{}} = Galleries.delete_subscription(subscription)
+      assert_raise Ecto.NoResultsError, fn -> Galleries.get_subscription!(subscription.id) end
+    end
+
+    test "change_subscription/1 returns a subscription changeset" do
+      subscription = subscription_fixture()
+      assert %Ecto.Changeset{} = Galleries.change_subscription(subscription)
+    end
+  end
 end