diff --git a/src/calibre/scraper/qt.py b/src/calibre/scraper/qt.py
index 462aecaf76..93f318b237 100644
--- a/src/calibre/scraper/qt.py
+++ b/src/calibre/scraper/qt.py
@@ -139,6 +139,7 @@ class Browser:
 
     def _send_command(self, cmd):
         with self.lock:
+            self._ensure_state()
             self.worker.stdin.write(json.dumps(cmd).encode())
             self.worker.stdin.write(b'\n')
             self.worker.stdin.flush()