diff --git a/telegram/audio.py b/telegram/audio.py
index 30342b7e0..c7a669d34 100644
--- a/telegram/audio.py
+++ b/telegram/audio.py
@@ -52,8 +52,8 @@ class Audio(TelegramObject):
         self.file_id = str(file_id)
         self.duration = int(duration)
         # Optionals
-        self.performer = str(kwargs.get('performer', ''))
-        self.title = str(kwargs.get('title', ''))
+        self.performer = kwargs.get('performer', '')
+        self.title = kwargs.get('title', '')
         self.mime_type = str(kwargs.get('mime_type', ''))
         self.file_size = int(kwargs.get('file_size', 0))
 
diff --git a/telegram/document.py b/telegram/document.py
index ff017ceae..d492774da 100644
--- a/telegram/document.py
+++ b/telegram/document.py
@@ -49,7 +49,7 @@ class Document(TelegramObject):
         self.file_id = str(file_id)
         # Optionals
         self.thumb = kwargs.get('thumb')
-        self.file_name = str(kwargs.get('file_name', ''))
+        self.file_name = kwargs.get('file_name', '')
         self.mime_type = str(kwargs.get('mime_type', ''))
         self.file_size = int(kwargs.get('file_size', 0))