diff --git a/backtesting/_plotting.py b/backtesting/_plotting.py
index c0283577..d4dcfeb7 100644
--- a/backtesting/_plotting.py
+++ b/backtesting/_plotting.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import re
 import sys
diff --git a/backtesting/_stats.py b/backtesting/_stats.py
index 09a30f07..2d8de0ca 100644
--- a/backtesting/_stats.py
+++ b/backtesting/_stats.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import TYPE_CHECKING, List, Union
 
 import numpy as np
diff --git a/backtesting/_util.py b/backtesting/_util.py
index 9d8c5edd..f1bbd527 100644
--- a/backtesting/_util.py
+++ b/backtesting/_util.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import warnings
 from numbers import Number
 from typing import Dict, List, Optional, Sequence, Union, cast
diff --git a/backtesting/backtesting.py b/backtesting/backtesting.py
index d90f4b2f..19312f12 100644
--- a/backtesting/backtesting.py
+++ b/backtesting/backtesting.py
@@ -5,6 +5,9 @@
 
     from backtesting import Backtest, Strategy
 """
+
+from __future__ import annotations
+
 import multiprocessing as mp
 import os
 import sys
@@ -200,9 +203,10 @@ def buy(self, *,
             stop: Optional[float] = None,
             sl: Optional[float] = None,
             tp: Optional[float] = None,
-            tag: object = None):
+            tag: object = None) -> 'Order':
         """
-        Place a new long order. For explanation of parameters, see `Order` and its properties.
+        Place a new long order and return it. For explanation of parameters, see `Order`
+        and its properties.
 
         See `Position.close()` and `Trade.close()` for closing existing positions.
 
@@ -218,9 +222,10 @@ def sell(self, *,
              stop: Optional[float] = None,
              sl: Optional[float] = None,
              tp: Optional[float] = None,
-             tag: object = None):
+             tag: object = None) -> 'Order':
         """
-        Place a new short order. For explanation of parameters, see `Order` and its properties.
+        Place a new short order and return it. For explanation of parameters, see `Order`
+        and its properties.
 
         See also `Strategy.buy()`.
 
@@ -745,7 +750,7 @@ def new_order(self,
                   tp: Optional[float] = None,
                   tag: object = None,
                   *,
-                  trade: Optional[Trade] = None):
+                  trade: Optional[Trade] = None) -> Order:
         """
         Argument size indicates whether the order is long or short
         """
diff --git a/backtesting/lib.py b/backtesting/lib.py
index d66d5d00..6164c86f 100644
--- a/backtesting/lib.py
+++ b/backtesting/lib.py
@@ -11,6 +11,8 @@
 [issue tracker]: https://github.com/kernc/backtesting.py
 """
 
+from __future__ import annotations
+
 from collections import OrderedDict
 from inspect import currentframe
 from itertools import compress
diff --git a/backtesting/test/__init__.py b/backtesting/test/__init__.py
index 142d2498..e1de19e6 100644
--- a/backtesting/test/__init__.py
+++ b/backtesting/test/__init__.py
@@ -1,4 +1,7 @@
 """Data and utilities for testing."""
+
+from __future__ import annotations
+
 import pandas as pd