diff --git a/telebot/asyncio_handler_backends.py b/telebot/asyncio_handler_backends.py
index 99a7b17..a565023 100644
--- a/telebot/asyncio_handler_backends.py
+++ b/telebot/asyncio_handler_backends.py
@@ -74,17 +74,18 @@ class StatesGroup:
             my_state = State() # returns my_state:State string.
     """
     def __init_subclass__(cls) -> None:
-
+        state_list = []
         for name, value in cls.__dict__.items():
             if not name.startswith('__') and not callable(value) and isinstance(value, State):
                 # change value of that variable
                 value.name = ':'.join((cls.__name__, name))
                 value.group = cls
+                state_list.append(value)
+        cls._state_list = state_list
 
     @property
     def state_list(self):
-        return [value for name, value in self.__dict__.items()
-                if not name.startswith('__') and not callable(value) and isinstance(value, State)]
+        return self._state_list
 
 
 class SkipHandler:
diff --git a/telebot/handler_backends.py b/telebot/handler_backends.py
index fda6997..2e4f86e 100644
--- a/telebot/handler_backends.py
+++ b/telebot/handler_backends.py
@@ -185,16 +185,18 @@ class StatesGroup:
             my_state = State() # returns my_state:State string.
     """
     def __init_subclass__(cls) -> None:
+        state_list = []
         for name, value in cls.__dict__.items():
             if not name.startswith('__') and not callable(value) and isinstance(value, State):
                 # change value of that variable
                 value.name = ':'.join((cls.__name__, name))
                 value.group = cls
+                state_list.append(value)
+        cls._state_list = state_list
 
     @property
     def state_list(self):
-        return [value for name, value in self.__dict__.items()
-                if not name.startswith('__') and not callable(value) and isinstance(value, State)]
+        return self._state_list
 
 
 class BaseMiddleware: