diff --git a/normandy/recipes/filters.py b/normandy/recipes/filters.py
index abfa60fb6..532202cd4 100644
--- a/normandy/recipes/filters.py
+++ b/normandy/recipes/filters.py
@@ -602,7 +602,7 @@ class WindowsVersionFilter(BaseComparisonFilter):
         ``windows_version``
 
     .. attribute:: value
-        string, must be one of the following: 6.1, 6.2, 6.3, 10.0
+        number, decimal, must be one of the following: 6.1, 6.2, 6.3, 10.0
 
        :example: ``6.1``
 
@@ -614,7 +614,7 @@ class WindowsVersionFilter(BaseComparisonFilter):
     """
 
     type = "windows_version"
-    value = serializers.CharField()
+    value = serializers.DecimalField(max_digits=3, decimal_places=1)
 
     @property
     def left_of_operator(self):
@@ -626,7 +626,7 @@ def to_jexl(self):
     def validate_value(self, value):
         from normandy.recipes.models import WindowsVersion
 
-        if not WindowsVersion.objects.filter(slug=value).exists():
+        if not WindowsVersion.objects.filter(nt_version=value).exists():
             raise serializers.ValidationError(f"Unrecognized windows version slug {value!r}")
 
         return value
@@ -700,6 +700,7 @@ def capabilities(self):
         PrefExistsFilter,
         PrefCompareFilter,
         PrefUserSetFilter,
+        WindowsVersionFilter,
     ]
 }
 
diff --git a/normandy/recipes/management/commands/initial_data.py b/normandy/recipes/management/commands/initial_data.py
index 2da072fc6..0b4a0999f 100644
--- a/normandy/recipes/management/commands/initial_data.py
+++ b/normandy/recipes/management/commands/initial_data.py
@@ -45,13 +45,13 @@ def add_countries(self):
 
     def add_windows_versions(self):
         self.stdout.write("Adding Windows Versions...", ending="")
-        versions = {
-            "6.1": "Windows 7",
-            "6.2": "Windows 8",
-            "6.3": "Windows 8.1",
-            "10.0": "Windows 10.0",
-        }
-
-        for slug, name in versions.items():
-            WindowsVersion.objects.update_or_create(slug=slug, defaults={"name": name})
+        versions = [
+            (6.1, "Windows 7"),
+            (6.2, "Windows 8"),
+            (6.3, "Windows 8.1"),
+            (10.0, "Windows 10"),
+        ]
+
+        for nt_version, name in versions:
+            WindowsVersion.objects.update_or_create(nt_version=nt_version, defaults={"name": name})
         self.stdout.write("Done")
diff --git a/normandy/recipes/migrations/0018_windowsversion.py b/normandy/recipes/migrations/0018_windowsversion.py
index fcf1595e6..04b3b93c3 100644
--- a/normandy/recipes/migrations/0018_windowsversion.py
+++ b/normandy/recipes/migrations/0018_windowsversion.py
@@ -1,4 +1,4 @@
-# Generated by Django 2.2.10 on 2020-03-16 23:24
+# Generated by Django 2.2.10 on 2020-03-18 20:48
 
 from django.db import migrations, models
 
@@ -17,9 +17,9 @@ class Migration(migrations.Migration):
                         auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
                     ),
                 ),
-                ("slug", models.CharField(max_length=255, unique=True)),
+                ("nt_version", models.DecimalField(decimal_places=1, max_digits=3)),
                 ("name", models.CharField(max_length=255)),
             ],
-            options={"ordering": ("slug",)},
+            options={"ordering": ("nt_version",)},
         )
     ]
diff --git a/normandy/recipes/models.py b/normandy/recipes/models.py
index f2a122647..30a69c9f0 100644
--- a/normandy/recipes/models.py
+++ b/normandy/recipes/models.py
@@ -45,14 +45,14 @@ def __repr__(self):
 
 
 class WindowsVersion(models.Model):
-    slug = models.CharField(max_length=255, unique=True)
+    nt_version = models.DecimalField(max_digits=3, decimal_places=1)
     name = models.CharField(max_length=255)
 
     class Meta:
-        ordering = ("slug",)
+        ordering = ("nt_version",)
 
     def __repr__(self):
-        return "<Windows Version {}>".format(self.slug)
+        return "<Windows Version {}>".format(self.nt_version)
 
 
 class Country(models.Model):
diff --git a/normandy/recipes/tests/__init__.py b/normandy/recipes/tests/__init__.py
index fcf96dbbe..765858324 100644
--- a/normandy/recipes/tests/__init__.py
+++ b/normandy/recipes/tests/__init__.py
@@ -34,9 +34,9 @@ class Meta:
 class WindowsVersionFactory(factory.DjangoModelFactory):
     class Meta:
         model = WindowsVersion
-        django_get_or_create = ("slug",)
+        django_get_or_create = ("nt_version",)
 
-    slug = "6.1"
+    nt_version = 6.1
     name = "Windows 7"
 
 
diff --git a/normandy/recipes/tests/test_filters.py b/normandy/recipes/tests/test_filters.py
index 3c979067d..0b678061d 100644
--- a/normandy/recipes/tests/test_filters.py
+++ b/normandy/recipes/tests/test_filters.py
@@ -156,8 +156,8 @@ def test_generates_jexl_error_on_bad_comparison(self):
 
 
 class TestWindowsVersionFilter(FilterTestsBase):
-    def create_basic_filter(self, value="6.1", comparison="equal"):
-        WindowsVersionFactory(slug="6.1")
+    def create_basic_filter(self, value=6.1, comparison="equal"):
+        WindowsVersionFactory(nt_version=6.1)
 
         return WindowsVersionFilter.create(value=value, comparison=comparison)