diff --git a/tljh/requirements-hub-env.txt b/tljh/requirements-hub-env.txt
index 556ad19..25bf123 100644
--- a/tljh/requirements-hub-env.txt
+++ b/tljh/requirements-hub-env.txt
@@ -27,4 +27,5 @@ jupyterhub-idle-culler>=1.2.1,<2
 #
 pycurl>=7.45.2,<8
 
-filelock>=3.13.3,<4
+# filelock is used to help us do atomic operations on config file(s)
+filelock>=3.15.4,<4