diff --git a/kfet/open/tests.py b/kfet/open/tests.py
index 455f2cef..7918ace7 100644
--- a/kfet/open/tests.py
+++ b/kfet/open/tests.py
@@ -18,7 +18,7 @@ class OpenKfetTest(ChannelTestCase):
 
     def setUp(self):
         self.kfet_open = OpenKfet(
-            cache_prefix="test_kfetopen_%s" % random.randrange(2 ** 20)
+            cache_prefix="test_kfetopen_%s" % random.randrange(2**20)
         )
         self.addCleanup(self.kfet_open.clear_cache)
 
@@ -145,7 +145,7 @@ class OpenKfetViewsTest(ChannelTestCase):
         self.c_a.login(username="admin", password="admin")
 
         self.kfet_open = OpenKfet(
-            cache_prefix="test_kfetopen_%s" % random.randrange(2 ** 20)
+            cache_prefix="test_kfetopen_%s" % random.randrange(2**20)
         )
         self.addCleanup(self.kfet_open.clear_cache)
 
@@ -256,7 +256,7 @@ class OpenKfetScenarioTest(ChannelTestCase):
         )
 
         self.kfet_open = OpenKfet(
-            cache_prefix="test_kfetopen_%s" % random.randrange(2 ** 20)
+            cache_prefix="test_kfetopen_%s" % random.randrange(2**20)
         )
         self.addCleanup(self.kfet_open.clear_cache)