diff --git a/aiogram/dispatcher/event/observer.py b/aiogram/dispatcher/event/observer.py
index 7f221fb4..096a2254 100644
--- a/aiogram/dispatcher/event/observer.py
+++ b/aiogram/dispatcher/event/observer.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import copy
 from typing import TYPE_CHECKING, Any, Dict, List, Type
 
 from pydantic import ValidationError
@@ -39,10 +40,12 @@ class EventObserver:
 
     async def trigger(self, *args, **kwargs):
         for handler in self.handlers:
+            kwargs_copy = copy.copy(kwargs)
             result, data = await handler.check(*args, **kwargs)
             if result:
+                kwargs_copy.update(data)
                 try:
-                    yield await handler.call(*args, **data)
+                    yield await handler.call(*args, **kwargs_copy)
                 except SkipHandler:
                     continue
 
diff --git a/tests/test_dispatcher/test_event/test_observer.py b/tests/test_dispatcher/test_event/test_observer.py
new file mode 100644
index 00000000..f3f1a82b
--- /dev/null
+++ b/tests/test_dispatcher/test_event/test_observer.py
@@ -0,0 +1,110 @@
+import functools
+from typing import Any, NoReturn
+
+import pytest
+
+from aiogram.dispatcher.event.handler import HandlerObject
+from aiogram.dispatcher.event.observer import EventObserver, SkipHandler
+
+
+async def my_handler(event: Any, index: int = 0) -> Any:
+    return event
+
+
+async def skip_my_handler(event: Any) -> NoReturn:
+    raise SkipHandler()
+
+
+async def pipe_handler(*args, **kwargs):
+    return args, kwargs
+
+
+class TestEventObserver:
+    @pytest.mark.parametrize(
+        "count,handler,filters",
+        (
+            pytest.param(5, my_handler, []),
+            pytest.param(3, my_handler, [lambda event: True]),
+            pytest.param(
+                2,
+                my_handler,
+                [lambda event: True, lambda event: False, lambda event: {"ok": True}],
+            ),
+        ),
+    )
+    def test_register_filters(self, count, handler, filters):
+        observer = EventObserver()
+
+        for index in range(count):
+            wrapped_handler = functools.partial(handler, index=index)
+            observer.register(wrapped_handler, *filters)
+            registered_handler = observer.handlers[index]
+
+            assert len(observer.handlers) == index + 1
+            assert isinstance(registered_handler, HandlerObject)
+            assert registered_handler.callback == wrapped_handler
+            assert registered_handler.awaitable
+            assert len(registered_handler.filters) == len(filters)
+
+    @pytest.mark.parametrize(
+        "count,handler,filters",
+        (
+            pytest.param(5, my_handler, []),
+            pytest.param(3, my_handler, [lambda event: True]),
+            pytest.param(
+                2,
+                my_handler,
+                [lambda event: True, lambda event: False, lambda event: {"ok": True}],
+            ),
+        ),
+    )
+    def test_register_filters_via_decorator(self, count, handler, filters):
+        observer = EventObserver()
+
+        for index in range(count):
+            wrapped_handler = functools.partial(handler, index=index)
+            observer(*filters)(wrapped_handler)
+            registered_handler = observer.handlers[index]
+
+            assert len(observer.handlers) == index + 1
+            assert isinstance(registered_handler, HandlerObject)
+            assert registered_handler.callback == wrapped_handler
+            assert registered_handler.awaitable
+            assert len(registered_handler.filters) == len(filters)
+
+    @pytest.mark.asyncio
+    async def test_trigger_rejected(self):
+        observer = EventObserver()
+        observer.register(my_handler, lambda event: False)
+
+        results = [result async for result in observer.trigger(42)]
+        assert results == []
+
+    @pytest.mark.asyncio
+    async def test_trigger_accepted_bool(self):
+        observer = EventObserver()
+        observer.register(my_handler, lambda event: True)
+
+        results = [result async for result in observer.trigger(42)]
+        assert results == [42]
+
+    @pytest.mark.asyncio
+    async def test_trigger_with_skip(self):
+        observer = EventObserver()
+        observer.register(skip_my_handler, lambda event: True)
+        observer.register(my_handler, lambda event: False)
+        observer.register(my_handler, lambda event: True)
+
+        results = [result async for result in observer.trigger(42)]
+        assert results == [42]
+
+    @pytest.mark.asyncio
+    async def test_trigger_right_context_in_handlers(self):
+        observer = EventObserver()
+        observer.register(
+            pipe_handler, lambda event: {"a": 1}, lambda event: False
+        )  # {"a": 1} should not be in result
+        observer.register(pipe_handler, lambda event: {"b": 2})
+
+        results = [result async for result in observer.trigger(42)]
+        assert results == [((42,), {"b": 2})]