diff --git a/lookyloo/default/abstractmanager.py b/lookyloo/default/abstractmanager.py
index 26e8f1b..3833fb6 100644
--- a/lookyloo/default/abstractmanager.py
+++ b/lookyloo/default/abstractmanager.py
@@ -84,6 +84,8 @@ class AbstractManager(ABC):
         pass
 
     def _kill_process(self):
+        if self.process is None:
+            return
         kill_order = [signal.SIGWINCH, signal.SIGTERM, signal.SIGINT, signal.SIGKILL]
         for sig in kill_order:
             if self.process.poll() is None: