diff --git a/eden/scm/edenscm/hgext/debugshell.py b/eden/scm/edenscm/hgext/debugshell.py
index 4430c57c7b..788a531ffb 100644
--- a/eden/scm/edenscm/hgext/debugshell.py
+++ b/eden/scm/edenscm/hgext/debugshell.py
@@ -16,6 +16,7 @@ from __future__ import absolute_import
 import os
 import shlex
 import sys
+import time
 
 import bindings
 import edenscm
@@ -117,6 +118,10 @@ def debugshell(ui, repo, *args, **opts):
 
 
 def _startipython(ui, repo):
+    # IPython requires time.clock. It is missing on Windows. Polyfill it.
+    if getattr(time, "clock", None) is None:
+        time.clock = time.time
+
     from IPython.terminal.embed import InteractiveShellEmbed
     from IPython.terminal.ipapp import load_default_config