diff --git a/zinnia/settings.py b/zinnia/settings.py
index <HASH>..<HASH> 100644
--- a/zinnia/settings.py
+++ b/zinnia/settings.py
@@ -83,7 +83,7 @@ COMPARISON_FIELDS = getattr(settings, 'ZINNIA_COMPARISON_FIELDS',
                              'excerpt', 'image_caption'])
 
 SPAM_CHECKER_BACKENDS = getattr(settings, 'ZINNIA_SPAM_CHECKER_BACKENDS',
-                                ())
+                                [])
 
 URL_SHORTENER_BACKEND = getattr(settings, 'ZINNIA_URL_SHORTENER_BACKEND',
                                 'zinnia.url_shortener.backends.default')
SPAM_CHECKER_BACKENDS is now a list instead of a tuple for consistency