diff --git a/pyinfra/visitor/response_formatter/formatter.py b/pyinfra/visitor/response_formatter/formatter.py
index 9364bb4..589defc 100644
--- a/pyinfra/visitor/response_formatter/formatter.py
+++ b/pyinfra/visitor/response_formatter/formatter.py
@@ -3,7 +3,7 @@ import abc
 
 class ResponseFormatter(abc.ABC):
     def __call__(self, message):
-        return self.format(message)
+        return map(self.format, message)
 
     @abc.abstractmethod
     def format(self, message):