diff --git a/app/models/rental.rb b/app/models/rental.rb
index 397b590d1..d752985c3 100644
--- a/app/models/rental.rb
+++ b/app/models/rental.rb
@@ -4,5 +4,5 @@ class Rental < ApplicationRecord
 
   validates :customer_id, presence: true
   validates :movie_id, presence: true
-  validates :due_date, presence: true 
+  validates :due_date, presence: true
 end
diff --git a/db/migrate/20171107212027_add_foreign_keys_to_rentals_model.rb b/db/migrate/20171107212027_add_foreign_keys_to_rentals_model.rb
new file mode 100644
index 000000000..4006797e6
--- /dev/null
+++ b/db/migrate/20171107212027_add_foreign_keys_to_rentals_model.rb
@@ -0,0 +1,6 @@
+class AddForeignKeysToRentalsModel < ActiveRecord::Migration[5.1]
+  def change
+    add_foreign_key :rentals, :movies
+    add_foreign_key :rentals, :customers
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6f7142676..aaf7030fa 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20171107181648) do
+ActiveRecord::Schema.define(version: 20171107212027) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -46,4 +46,6 @@
     t.boolean "checked_out"
   end
 
+  add_foreign_key "rentals", "customers"
+  add_foreign_key "rentals", "movies"
 end
diff --git a/test/models/customer_test.rb b/test/models/customer_test.rb
index a6cd4499c..714fa19af 100644
--- a/test/models/customer_test.rb
+++ b/test/models/customer_test.rb
@@ -3,6 +3,23 @@
 describe Customer do
   let(:customer) { Customer.new }
 
+  describe "relationships" do
+    it "has a collection of rentals" do
+      c = Customer.new(name: "Mira")
+      c. save
+      m_id = Movie.first.id
+      c_id = c.id
+
+      c.must_respond_to :rentals
+      c.rentals.must_be :empty?
+
+      r = Rental.new(customer_id: "c_id", movie_id: "m_id", due_date: Date.new(2017, 12, 1))
+
+      c.rentals << r
+      c.rentals.must_include r
+    end # collection of rentals
+  end # relationships
+
   describe "validations" do
     it "can be created if all fields are provided" do
       start_count = Customer.count
diff --git a/test/models/rental_test.rb b/test/models/rental_test.rb
index 4b9e9633b..715635e8a 100644
--- a/test/models/rental_test.rb
+++ b/test/models/rental_test.rb
@@ -23,4 +23,23 @@
       Rental.count.must_equal start_count
     end
   end # validations
+
+  describe "relationships" do
+    let(:m) { Movie.first }
+    let(:c) { Customer.first }
+    let(:r) {
+      Rental.new(customer_id: c.id, movie_id: m.id, due_date: Date.new(2017, 12, 1))
+    }
+    it "belongs to a movie" do
+      r.must_respond_to :customer
+      r.customer.must_equal c
+      r.customer.id.must_equal c.id
+    end
+
+    it "belongs to a customer" do
+      r.must_respond_to :movie
+      r.movie.must_equal m
+      r.movie.id.must_equal m.id
+    end
+  end # relationships
 end # Rental