diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index faa93ecc173cd93377beca9f55cd620b63bdc473..4c2a4cfeb08fe5c98a8258ddfd127e7596d35c52 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -2088,8 +2088,7 @@ def [](key)
 
         def each
           node = self
-          loop do
-            break if node.equal? NULL
+          until node.equal? NULL
             yield node
             node = node.parent
           end