diff --git a/lib/tfw/components/file_manager/file_manager.py b/lib/tfw/components/file_manager/file_manager.py
index 967e06f..0e4fc6a 100644
--- a/lib/tfw/components/file_manager/file_manager.py
+++ b/lib/tfw/components/file_manager/file_manager.py
@@ -65,13 +65,13 @@ class FileManager:  # pylint: disable=too-many-instance-attributes
 
     @property
     def file_contents(self):
-        with open(self._filepath(self.filename), 'r', errors='surrogateescape') as ifile:
-            return ifile.read()
+        with open(self._filepath(self.filename), 'rb', buffering=0) as ifile:
+            return ifile.read().decode(errors='surrogateescape')
 
     @file_contents.setter
     def file_contents(self, value):
-        with open(self._filepath(self.filename), 'w', errors='surrogateescape') as ofile:
-            ofile.write(value)
+        with open(self._filepath(self.filename), 'wb', buffering=0) as ofile:
+            ofile.write(value.encode())
 
     def _is_in_allowed_dir(self, path):
         return any(