diff --git a/horizon/base.py b/horizon/base.py
index a373a70df8..93630e735c 100644
--- a/horizon/base.py
+++ b/horizon/base.py
@@ -153,7 +153,7 @@ class HorizonComponent(object):
             for rule in self.policy_rules:
                 rule_param = rule
                 if not any(isinstance(r, (list, tuple)) for r in rule):
-                    rule_param = list(rule)
+                    rule_param = (rule,)
                 if policy_check(rule_param, request):
                     return True
             return False