diff --git a/qutebrowser/misc/ipc.py b/qutebrowser/misc/ipc.py
index 4f77379d0..4afae78e9 100644
--- a/qutebrowser/misc/ipc.py
+++ b/qutebrowser/misc/ipc.py
@@ -362,6 +362,9 @@ class IPCServer(QObject):
     @pyqtSlot()
     def on_timeout(self):
         """Cancel the current connection if it was idle for too long."""
+        if self._socket is None:
+            log.ipc.error("on_timeout got called with None socket!")
+            return
         log.ipc.error("IPC connection timed out "
                       "(socket 0x{:x}).".format(id(self._socket)))
         self._socket.disconnectFromServer()