diff --git a/zerver/lib/timeout.py b/zerver/lib/timeout.py
index c85d73cc1f..46ef82c083 100644
--- a/zerver/lib/timeout.py
+++ b/zerver/lib/timeout.py
@@ -1,4 +1,5 @@
 import ctypes
+import logging
 import sys
 import threading
 import time
@@ -82,6 +83,12 @@ def timeout(timeout: float, func: Callable[[], ResultT]) -> ResultT:
             # Re-raise the exception we sent, if possible, so the
             # stacktrace originates in the slow code
             raise thread.exc_info[1].with_traceback(thread.exc_info[2])
+        # If we don't have that for some reason (e.g. we failed to
+        # kill it), just raise from here; the thread _may still be
+        # running_ because it failed to see any of our exceptions, and
+        # we just ignore it.
+        if thread.is_alive():
+            logging.warning("Failed to time out backend thread")
         raise TimeoutExpired
 
     if thread.exc_info[1] is not None: