diff --git a/nonebot/adapters/_formatter.py b/nonebot/adapters/_formatter.py
index 0e1e59b7..c0449fd6 100644
--- a/nonebot/adapters/_formatter.py
+++ b/nonebot/adapters/_formatter.py
@@ -105,4 +105,4 @@ class MessageFormatter(Formatter, Generic[TM]):
                                              [""])), auto_arg_index
 
     def format_field(self, value: Any, format_spec: str) -> Any:
-        return super().format_field(value, format_spec) if format_spec else None
+        return super().format_field(value, format_spec) if format_spec else value