diff --git a/IPython/frontend/qt/manager.py b/IPython/frontend/qt/manager.py
index 4faac2b..e7b877b 100644
--- a/IPython/frontend/qt/manager.py
+++ b/IPython/frontend/qt/manager.py
@@ -40,7 +40,7 @@ class QtKernelManager(KernelManager, QtKernelManagerMixin):
                     config=self.config,
                     log=self.log,
                 )
-                self._restarter.register_callback(self._handle_kernel_restarted)
+                self._restarter.add_callback(self._handle_kernel_restarted)
             self._restarter.start()
 
     def stop_restarter(self):