diff --git a/app/experimenter/experiments/forms.py b/app/experimenter/experiments/forms.py
index 8031777959..91cfd6fec3 100644
--- a/app/experimenter/experiments/forms.py
+++ b/app/experimenter/experiments/forms.py
@@ -267,9 +267,11 @@ def clean(self):
                 form._errors["name"] = ["All branches must have a unique name"]
 
 
-class ExperimentVariantsPrefFormSet(BaseInlineFormSet):
+class ExperimentVariantsPrefFormSet(ExperimentVariantsFormSet):
 
     def clean(self):
+        super().clean()
+
         alive_forms = [
             form
             for form in self.forms
diff --git a/app/experimenter/experiments/tests/test_forms.py b/app/experimenter/experiments/tests/test_forms.py
index c5fb2d808b..8955d607b6 100644
--- a/app/experimenter/experiments/tests/test_forms.py
+++ b/app/experimenter/experiments/tests/test_forms.py
@@ -4,9 +4,9 @@
 
 from django import forms
 from django.core.exceptions import ValidationError
-from django.forms import inlineformset_factory
 from django.test import TestCase
 from django.utils import timezone
+from parameterized import parameterized_class
 
 from experimenter.experiments.forms import (
     BugzillaURLField,
@@ -21,7 +21,6 @@
     ExperimentVariantAddonForm,
     ExperimentVariantPrefForm,
     ExperimentVariantsAddonForm,
-    ExperimentVariantsFormSet,
     ExperimentVariantsPrefForm,
     JSONField,
 )
@@ -256,17 +255,27 @@ def test_empty_slug_raises_error(self):
         self.assertFalse(form.is_valid())
 
 
-class TestExperimentVariantsFormSet(TestCase):
+@parameterized_class(
+    ["form_class"],
+    [[ExperimentVariantsAddonForm], [ExperimentVariantsPrefForm]],
+)
+class TestExperimentVariantsFormSet(MockRequestMixin, TestCase):
 
     def setUp(self):
-        self.FormSet = inlineformset_factory(
-            formset=ExperimentVariantsFormSet,
-            model=ExperimentVariant,
-            parent_model=Experiment,
-            fields=["is_control", "ratio", "name", "slug", "description"],
+        super().setUp()
+
+        self.experiment = ExperimentFactory.create_with_status(
+            Experiment.STATUS_DRAFT, num_variants=0
         )
 
         self.data = {
+            "population_percent": "10",
+            "firefox_version": Experiment.VERSION_CHOICES[-1][0],
+            "firefox_channel": Experiment.CHANNEL_NIGHTLY,
+            "client_matching": "en-us only please",
+            "pref_key": "browser.test.example",
+            "pref_type": Experiment.PREF_TYPE_STR,
+            "pref_branch": Experiment.PREF_BRANCH_DEFAULT,
             "variants-TOTAL_FORMS": "3",
             "variants-INITIAL_FORMS": "0",
             "variants-MIN_NUM_FORMS": "0",
@@ -274,52 +283,69 @@ def setUp(self):
             "variants-0-is_control": True,
             "variants-0-ratio": "34",
             "variants-0-name": "control name",
-            "variants-0-slug": "control-slug",
             "variants-0-description": "control desc",
+            "variants-0-value": '"control value"',
             "variants-1-is_control": False,
             "variants-1-ratio": "33",
             "variants-1-name": "branch 1 name",
-            "variants-1-slug": "branch-1-slug",
             "variants-1-description": "branch 1 desc",
+            "variants-1-value": '"branch 1 value"',
             "variants-2-is_control": False,
             "variants-2-ratio": "33",
             "variants-2-name": "branch 2 name",
-            "variants-2-slug": "branch-2-slug",
             "variants-2-description": "branch 2 desc",
+            "variants-2-value": '"branch 2 value"',
         }
 
-    def test_formset_valid_if_sizes_sum_to_100(self):
-        formset = self.FormSet(data=self.data)
-        self.assertTrue(formset.is_valid())
+    def test_form_valid_if_sizes_sum_to_100(self):
+        self.data["variants-0-ratio"] = "34"
+        self.data["variants-1-ratio"] = "33"
+        self.data["variants-2-ratio"] = "33"
+        form = self.form_class(
+            request=self.request, data=self.data, instance=self.experiment
+        )
+        self.assertTrue(form.is_valid())
 
-    def test_formset_invalid_if_sizes_sum_to_less_than_100(self):
-        self.data["variants-0-ratio"] = 30
-        formset = self.FormSet(data=self.data)
-        self.assertFalse(formset.is_valid())
+    def test_form_invalid_if_sizes_sum_to_less_than_100(self):
+        self.data["variants-0-ratio"] = "33"
+        self.data["variants-1-ratio"] = "33"
+        self.data["variants-2-ratio"] = "33"
+        form = self.form_class(
+            request=self.request, data=self.data, instance=self.experiment
+        )
+        self.assertFalse(form.is_valid())
 
-        for form in formset.forms:
+        for form in form.variants_formset.forms:
             self.assertIn("ratio", form.errors)
 
-    def test_formset_invalid_if_sizes_sum_to_more_than_100(self):
-        self.data["variants-0-ratio"] = 40
-        formset = self.FormSet(data=self.data)
-        self.assertFalse(formset.is_valid())
+    def test_form_invalid_if_sizes_sum_to_more_than_100(self):
+        self.data["variants-0-ratio"] = "35"
+        self.data["variants-1-ratio"] = "33"
+        self.data["variants-2-ratio"] = "33"
+        form = self.form_class(
+            request=self.request, data=self.data, instance=self.experiment
+        )
+        self.assertFalse(form.is_valid())
 
-        for form in formset.forms:
+        for form in form.variants_formset.forms:
             self.assertIn("ratio", form.errors)
 
-    def test_formset_invalid_if_duplicate_slugs_appear(self):
-        self.data["variants-0-slug"] = self.data["variants-1-slug"]
-        formset = self.FormSet(data=self.data)
-        self.assertFalse(formset.is_valid())
+    def test_form_invalid_if_duplicate_names_appear(self):
+        self.data["variants-0-name"] = self.data["variants-1-name"]
+        form = self.form_class(
+            request=self.request, data=self.data, instance=self.experiment
+        )
+        self.assertFalse(form.is_valid())
 
-        for form in formset.forms:
+        for form in form.variants_formset.forms:
             self.assertIn("name", form.errors)
 
     def test_empty_branch_size_raises_validation_error(self):
         del self.data["variants-0-ratio"]
-        formset = self.FormSet(data=self.data)
-        self.assertFalse(formset.is_valid())
+        form = self.form_class(
+            request=self.request, data=self.data, instance=self.experiment
+        )
+        self.assertFalse(form.is_valid())
 
 
 class TestExperimentVariantsAddonForm(MockRequestMixin, TestCase):
diff --git a/app/requirements/default.txt b/app/requirements/default.txt
index 0498bcea08..e38836ae23 100644
--- a/app/requirements/default.txt
+++ b/app/requirements/default.txt
@@ -138,3 +138,6 @@ requests[security]==2.20.0 \
 whitenoise==4.1.2 \
     --hash=sha256:118ab3e5f815d380171b100b05b76de2a07612f422368a201a9ffdeefb2251c1 \
     --hash=sha256:42133ddd5229eeb6a0c9899496bdbe56c292394bf8666da77deeb27454c0456a
+parameterized==0.7.0 \
+    --hash=sha256:020343a281efcfe9b71b9028a91817f981202c14d72104b5a2fbe401dee25a18 \
+    --hash=sha256:d8c8837fb677ed2d5a93b9e2308ce0da3aeb58cf513120d501e0b7af14da78d5