diff --git a/hc/accounts/tests/test_profile.py b/hc/accounts/tests/test_profile.py
index 4318f079..ba7528cc 100644
--- a/hc/accounts/tests/test_profile.py
+++ b/hc/accounts/tests/test_profile.py
@@ -122,3 +122,18 @@ class ProfileTestCase(BaseTestCase):
         # to user's default team.
         self.bobs_profile.refresh_from_db()
         self.assertEqual(self.bobs_profile.current_team, self.bobs_profile)
+
+    def test_it_shows_badges(self):
+        self.client.login(username="alice@example.org", password="password")
+        Check.objects.create(user=self.alice, tags="foo a-B_1  baz@")
+        Check.objects.create(user=self.bob, tags="bobs-tag")
+
+        r = self.client.get("/accounts/profile/")
+        self.assertContains(r, "foo.svg")
+        self.assertContains(r, "a-B_1.svg")
+
+        # Expect badge URLs only for tags that match \w+
+        self.assertNotContains(r, "baz@.svg")
+
+        # Expect only Alice's tags
+        self.assertNotContains(r, "bobs-tag.svg")
diff --git a/hc/api/tests/test_badge.py b/hc/api/tests/test_badge.py
new file mode 100644
index 00000000..31042e52
--- /dev/null
+++ b/hc/api/tests/test_badge.py
@@ -0,0 +1,24 @@
+from django.conf import settings
+from django.core.signing import base64_hmac
+
+from hc.api.models import Check
+from hc.test import BaseTestCase
+
+
+class BadgeTestCase(BaseTestCase):
+
+    def setUp(self):
+        super(BadgeTestCase, self).setUp()
+        self.check = Check.objects.create(user=self.alice, tags="foo bar")
+
+    def test_it_rejects_bad_signature(self):
+        r = self.client.get("/badge/%s/12345678/foo.svg" % self.alice.username)
+        assert r.status_code == 400
+
+    def test_it_returns_svg(self):
+        sig = base64_hmac(str(self.alice.username), "foo", settings.SECRET_KEY)
+        sig = sig[:8].decode("utf-8")
+        url = "/badge/%s/%s/foo.svg" % (self.alice.username, sig)
+
+        r = self.client.get(url)
+        self.assertContains(r, "#4c1")
diff --git a/hc/lib/tests/__init__.py b/hc/lib/tests/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/hc/lib/tests/test_badges.py b/hc/lib/tests/test_badges.py
new file mode 100644
index 00000000..d5390e1e
--- /dev/null
+++ b/hc/lib/tests/test_badges.py
@@ -0,0 +1,18 @@
+from django.test import TestCase
+
+from hc.lib.badges import get_width, get_badge_svg
+
+
+class BadgesTestCase(TestCase):
+
+    def test_get_width_works(self):
+        self.assertEqual(get_width("mm"), 20)
+        # Default width for unknown characters is 7
+        self.assertEqual(get_width("@"), 7)
+
+    def test_it_makes_svg(self):
+        svg = get_badge_svg("foo", "up")
+        self.assertTrue("#4c1" in svg)
+
+        svg = get_badge_svg("bar", "down")
+        self.assertTrue("#e05d44" in svg)