diff --git a/notebook/tests/launchnotebook.py b/notebook/tests/launchnotebook.py
index 25ce8c81684..300c5202ddf 100644
--- a/notebook/tests/launchnotebook.py
+++ b/notebook/tests/launchnotebook.py
@@ -53,6 +53,8 @@ def wait_until_alive(cls):
         for _ in range(int(MAX_WAITTIME/POLL_INTERVAL)):
             try:
                 cls.fetch_url(url)
+            except ModuleNotFoundError as error:
+                raise ModuleNotFoundError(error)
             except Exception as e:
                 if not cls.notebook_thread.is_alive():
                     raise RuntimeError("The notebook server failed to start") from e