diff --git a/jupyter_client/manager.py b/jupyter_client/manager.py
index ea5530c58..fce232fb4 100644
--- a/jupyter_client/manager.py
+++ b/jupyter_client/manager.py
@@ -644,7 +644,7 @@ async def _kill_kernel(self):
                 if hasattr(signal, 'SIGKILL'):
                     await self.signal_kernel(signal.SIGKILL)
                 else:
-                    await self.kernel.kill()
+                    self.kernel.kill()
             except OSError as e:
                 # In Windows, we will get an Access Denied error if the process
                 # has already terminated. Ignore it.