diff --git a/taskiq_fastapi/initializator.py b/taskiq_fastapi/initializator.py
index f31a6f0..dc18fef 100644
--- a/taskiq_fastapi/initializator.py
+++ b/taskiq_fastapi/initializator.py
@@ -5,19 +5,21 @@
 from taskiq import AsyncBroker, TaskiqEvents, TaskiqState
 from taskiq.cli.utils import import_object
 
+PathOrAppOrFactory = Union[str, FastAPI, Callable[[], FastAPI]]
+
 
 def startup_event_generator(
     broker: AsyncBroker,
-    app_or_path: Union[str, FastAPI],
+    app_or_path: PathOrAppOrFactory,
 ) -> Callable[[TaskiqState], Awaitable[None]]:
     """
-    Generate shutdown event.
+    Generate startup event handler.
 
     This function takes FastAPI application path
     and runs startup event on broker's startup.
 
     :param broker: current broker.
-    :param app_path: fastapi application path.
+    :param app_or_path: application path or fastapi instance or callable that creates fastapi app instance.
     :returns: startup handler.
     """
 
@@ -48,7 +50,7 @@ def shutdown_event_generator(
     broker: AsyncBroker,
 ) -> Callable[[TaskiqState], Awaitable[None]]:
     """
-    Generate shutdown event.
+    Generate shutdown event handler.
 
     This function takes FastAPI application
     and runs shutdown event on broker's shutdown.
@@ -66,7 +68,7 @@ async def shutdown(state: TaskiqState) -> None:
     return shutdown
 
 
-def init(broker: AsyncBroker, app_or_path: Union[str, FastAPI]) -> None:
+def init(broker: AsyncBroker, app_or_path: PathOrAppOrFactory) -> None:
     """
     Add taskiq startup events.
 
@@ -78,7 +80,7 @@ def init(broker: AsyncBroker, app_or_path: Union[str, FastAPI]) -> None:
     startup events will run.
 
     :param broker: current broker to use.
-    :param app_path: path to fastapi application.
+    :param app_or_path: application path or fastapi instance or callable that creates fastapi app instance.
     """
     broker.add_event_handler(
         TaskiqEvents.WORKER_STARTUP,
@@ -102,7 +104,7 @@ def populate_dependency_context(
     This function injects the Request and HTTPConnection
     into the broker's dependency context.
 
-    It may be need to be called manually if you are using InMemoryBroker.
+    It may be needed to be called manually if you are using InMemoryBroker.
 
     :param broker: current broker to use.
     :param app: current application.