diff --git a/registrasion/controllers/cart.py b/registrasion/controllers/cart.py
index 59b308ed..d9307b39 100644
--- a/registrasion/controllers/cart.py
+++ b/registrasion/controllers/cart.py
@@ -211,6 +211,7 @@ class CartController(object):
             # Get the count of past uses of this discount condition
             # as this affects the total amount we're allowed to use now.
             past_uses = rego.DiscountItem.objects.filter(
+                cart__user=self.cart.user,
                 discount=discount.discount,
             )
             agg = past_uses.aggregate(Sum("quantity"))
diff --git a/registrasion/tests/test_cart.py b/registrasion/tests/test_cart.py
index c65011b9..d000b946 100644
--- a/registrasion/tests/test_cart.py
+++ b/registrasion/tests/test_cart.py
@@ -37,6 +37,7 @@ class RegistrationCartTestCase(SetTimeMixin, TestCase):
             description="This is a test category",
             order=10,
             render_type=rego.Category.RENDER_TYPE_RADIO,
+            required=False,
         )
         cls.CAT_1.save()
 
@@ -45,6 +46,7 @@ class RegistrationCartTestCase(SetTimeMixin, TestCase):
             description="This is a test category",
             order=10,
             render_type=rego.Category.RENDER_TYPE_RADIO,
+            required=False,
         )
         cls.CAT_2.save()
 
diff --git a/registrasion/tests/test_discount.py b/registrasion/tests/test_discount.py
index 5d325eff..6f943d0f 100644
--- a/registrasion/tests/test_discount.py
+++ b/registrasion/tests/test_discount.py
@@ -200,3 +200,17 @@ class DiscountTestCase(RegistrationCartTestCase):
         # There is one discount, and it should apply to the more expensive.
         self.assertEqual(1, len(discount_items))
         self.assertEqual(self.PROD_3, discount_items[0].product)
+
+    def test_discount_quantity_is_per_user(self):
+        self.add_discount_prod_1_includes_cat_2(quantity=1)
+
+        # Both users should be able to apply the same discount
+        # in the same way
+        for user in (self.USER_1, self.USER_2):
+            cart = CartController.for_user(user)
+            cart.add_to_cart(self.PROD_1, 1) # Enable the discount
+            cart.add_to_cart(self.PROD_3, 1)
+
+            discount_items = list(cart.cart.discountitem_set.all())
+            # The discount is applied.
+            self.assertEqual(1, len(discount_items))