diff --git a/benchmark/run.py b/benchmark/run.py
index 5120913..783aa07 100644
--- a/benchmark/run.py
+++ b/benchmark/run.py
@@ -1,10 +1,9 @@
 import timeit
 from pathlib import Path
 
-_parsers = []
 
 import pytomlpp
-_parsers.append(('pytomlpp', pytomlpp.loads))
+_parsers = [('pytomlpp', pytomlpp.loads)]
 
 try:
     import rtoml
diff --git a/src/pytomlpp/_io.py b/src/pytomlpp/_io.py
index 491741f..bfbf9f6 100644
--- a/src/pytomlpp/_io.py
+++ b/src/pytomlpp/_io.py
@@ -20,14 +20,15 @@ def dumps(data: Dict[Any, Any]) -> str:
     return _impl.dumps(data)
 
 
-def dump(data: Dict[Any, Any], fl: FilePathOrObject, mode: str = "w", encoding: Optional[str] = "utf-8") -> None:
+def dump(data: Dict[Any, Any], fl: FilePathOrObject, mode: str = "w", encoding: Optional[str] = None) -> None:
     """Serialise data to TOML file
 
     Args:
         data (Dict[Any, Any]): input data
         fl (FilePathOrObject): file like object or path
         mode (str, optional): mode to write the file, support "w", "wt" (text) or "wb" (binary). Defaults to "w".
-        encoding (str): defaults to utf-8, if None, local encoding is selected.
+        encoding (str): defaults to None. If None, local enconding will be selected. 
+        NOTE: ``If mode is binary mode, encoding optional argument will be negligible.``
     """
     data = _impl.dumps(data)
     if mode == "wb":
@@ -35,7 +36,7 @@ def dump(data: Dict[Any, Any], fl: FilePathOrObject, mode: str = "w", encoding:
     if hasattr(fl, "write"):
         fl.write(data)
         return
-    with open(fl, mode=mode, encoding=encoding or None) as fh:
+    with open(fl, mode=mode, encoding=encoding) as fh:
         fh.write(data)
 
 
@@ -51,21 +52,22 @@ def loads(data: str) -> Dict[Any, Any]:
     return _impl.loads(data)
 
 
-def load(fl: FilePathOrObject, mode: str = "r", encoding: Optional[str] = "utf-8") -> Dict[Any, Any]:
+def load(fl: FilePathOrObject, mode: str = "r", encoding: Optional[str] = None) -> Dict[Any, Any]:
     """Deserialise from TOML file to python dict.
 
     Args:
         fl (FilePathOrObject): file like object or path
         mode (str, optional): mode to read the file, support "r", "rt" (text) or "rb" (binary). Defaults to "r".
-
+        encoding (str): defaults to None. If None, local enconding will be selected. 
+        NOTE: ``If mode is binary mode, encoding optional argument will be negligible.``
+          
     Returns:
         Dict[Any, Any]: deserialised data
     """
-
     if hasattr(fl, "read"):
         data = fl.read()
     else:
-        with open(fl, mode=mode, encoding=encoding or None) as fh:
+        with open(fl, mode=mode, encoding=encoding) as fh:
             data = fh.read()
     if isinstance(data, bytes):
         return _impl.loads(data.decode("utf-8"))