diff --git a/test_themes/tests/test_new_page_templates.py b/test_themes/tests/test_new_page_templates.py
index 79e147be7..3cd5007a5 100644
--- a/test_themes/tests/test_new_page_templates.py
+++ b/test_themes/tests/test_new_page_templates.py
@@ -172,7 +172,7 @@ class TestNewPageTemplates(TransactionCase):
                             # Only look at blocks in website.snippets
                             html_tree = blocks_el[0]
                         for el in html_tree.xpath('//*[@class]'):
-                            classes = el.attrib['class'].split(' ')
+                            classes = el.attrib['class'].split()
                             classes_inventory.update(classes)
                             if len(classes) != len(set(classes)):
                                 errors.append("Using %r, view %r contains duplicate classes: %r" % (theme_name, view.key, classes))