diff --git a/pyrogram/session/session.py b/pyrogram/session/session.py
index d27c6a83..b68e3fa0 100644
--- a/pyrogram/session/session.py
+++ b/pyrogram/session/session.py
@@ -164,8 +164,11 @@ class Session:
         self.ping_thread_event.set()
         self.next_salt_thread_event.set()
 
-        self.ping_thread.join()
-        self.next_salt_thread.join()
+        if self.ping_thread is not None:
+            self.ping_thread.join()
+
+        if self.next_salt_thread is not None:
+            self.next_salt_thread.join()
 
         self.ping_thread_event.clear()
         self.next_salt_thread_event.clear()