diff --git a/libs/hbb_common b/libs/hbb_common
index 1f8463d72..01ee2f46e 160000
--- a/libs/hbb_common
+++ b/libs/hbb_common
@@ -1 +1 @@
-Subproject commit 1f8463d720e9d9452be75d3b5e584a787ad34385
+Subproject commit 01ee2f46ece493110510b8d8b5ca019488f33f7a
diff --git a/src/client/io_loop.rs b/src/client/io_loop.rs
index 411c3ea9b..9fc07895d 100644
--- a/src/client/io_loop.rs
+++ b/src/client/io_loop.rs
@@ -197,7 +197,9 @@ impl<T: InvokeUiSession> Remote<T> {
                     }
                     self.handle_disconnected(round);
                     // Close the WebRTC pc on this decline path too (no-op for TCP/WS); otherwise its
-                    // pc lingers in the global session cache until ICE decays on its own.
+                    // pc lingers in the global session cache until ICE decays on its own. The pc
+                    // and its teardown live on hbb_common's WebRTC I/O runtime, so this session
+                    // runtime's death on return affects neither.
                     peer.close_webrtc();
                     return;
                 }
@@ -347,7 +349,11 @@ impl<T: InvokeUiSession> Remote<T> {
                 log::debug!("Exit io_loop of id={}", self.handler.get_id());
                 // Close the WebRTC peer connection (if this session used it) so its pc is not left
                 // lingering in the global session cache after the session ends; dropping `peer`
-                // alone does not release it. No-op for TCP/WebSocket transports.
+                // alone does not release it. No-op for TCP/WebSocket transports. The pc, its
+                // sockets and pump tasks, and this close all live on hbb_common's WebRTC I/O
+                // runtime — nothing may run them on this session runtime, which is dropped the
+                // moment io_loop returns and would kill the teardown (or, if awaited under a
+                // timeout, cancel it after `close()` latches `is_closed`, stranding the pc).
                 peer.close_webrtc();
                 // Stop client audio server.
                 if let Some(s) = self.stop_voice_call_sender.take() {