diff --git a/bottle.py b/bottle.py
index 23fff762..d867d4be 100755
--- a/bottle.py
+++ b/bottle.py
@@ -2325,7 +2325,7 @@ def __iter__(self):
                 yield _hkey(key)
 
     def keys(self):
-        return [x for x in self]
+        return list(self)
 
     def __len__(self):
         return len(self.keys())