diff --git a/aggregator/apps.py b/aggregator/apps.py
index d912167..4a30c66 100644
--- a/aggregator/apps.py
+++ b/aggregator/apps.py
@@ -1,4 +1,5 @@
 from django.apps import AppConfig
+from django.db.models.signals import post_delete
 
 
 class AggregatorConfig(AppConfig):
@@ -6,9 +7,17 @@ class AggregatorConfig(AppConfig):
 
     def ready(self):
         self.register_config()
+        self.register_signals()
 
     def register_config(self):
         import djconfig
         from .forms import AggregatorAppConfigForm
 
         djconfig.register(AggregatorAppConfigForm)
+
+    def register_signals(self):
+        from .models import AggregationSource, Chat
+        from .signals import aggregation_source_deleted, chat_deleted
+
+        post_delete.connect(aggregation_source_deleted, sender=AggregationSource)
+        post_delete.connect(chat_deleted, sender=Chat)
diff --git a/aggregator/models.py b/aggregator/models.py
index 9558917..bd9ee43 100644
--- a/aggregator/models.py
+++ b/aggregator/models.py
@@ -48,8 +48,6 @@ class Chat(models.Model):
                         obj.photo.save(os.path.basename(path), f, save=True)
                 obj.photo_id = chat.photo.small_file_id
                 obj.save()
-        if created:
-            transaction.on_commit(lambda: collect_new_messages.delay(obj.pk))
         return obj
 
     def __str__(self):
diff --git a/aggregator/signals.py b/aggregator/signals.py
new file mode 100644
index 0000000..cb93ab0
--- /dev/null
+++ b/aggregator/signals.py
@@ -0,0 +1,24 @@
+from django.db import transaction
+from pyrogram import Error
+
+from .client import get_client
+from .models import Chat, AggregationSource
+from .tasks import collect_new_messages
+
+
+def aggregation_source_deleted(sender, instance: AggregationSource, **kwargs):
+    if not AggregationSource.objects.filter(chat_id=instance.chat_id):
+        Chat.objects.filter(chat_id=instance.chat_id).delete()
+
+
+def chat_created(sender, instance: Chat, created, **kwargs):
+    if created:
+        transaction.on_commit(lambda: collect_new_messages.delay(instance.pk))
+
+
+def chat_deleted(sender, instance: Chat, **kwargs):
+    with get_client() as client:
+        try:
+            client.leave_chat(instance.chat_id)
+        except Error:
+            pass