diff --git a/files/helpers/wrappers.py b/files/helpers/wrappers.py
index 6bd5672a8b..3f2466108d 100644
--- a/files/helpers/wrappers.py
+++ b/files/helpers/wrappers.py
@@ -9,6 +9,10 @@ import user_agents
 import time
 
 def calc_users(v):
+	# Some globals we expect aren't available when rendering error pages
+	if not g.agent or not ('session_id' in session):
+		return ''
+
 	loggedin = cache.get(f'{SITE}_loggedin') or {}
 	loggedout = cache.get(f'{SITE}_loggedout') or {}
 	timestamp = int(time.time())