diff --git a/project.env b/project.env
index c4308c0..0fc425a 100644
--- a/project.env
+++ b/project.env
@@ -3,7 +3,7 @@ PROJECT_NAME="stellars-jupyterhub-ds"
 PROJECT_DESCRIPTION="Multi-user JupyterHub 4 deployment platform with data science stack, GPU auto-detection, NativeAuthenticator, and isolated per-user environments spawned via DockerSpawner"
 
 # Version
-VERSION="3.5.40_cuda-12.9.1_jh-5.4.2"
+VERSION="3.5.43_cuda-12.9.1_jh-5.4.2"
 VERSION_COMMENT="Admin user creation with auto-generated passwords, NativeAuth sync, custom templates"
 RELEASE_TAG="RELEASE_3.2.11"
 RELEASE_DATE="2025-11-09"
diff --git a/services/jupyterhub/conf/bin/custom_handlers.py b/services/jupyterhub/conf/bin/custom_handlers.py
index f6a452e..b8bcc06 100755
--- a/services/jupyterhub/conf/bin/custom_handlers.py
+++ b/services/jupyterhub/conf/bin/custom_handlers.py
@@ -53,7 +53,7 @@ def encode_username_for_docker(username):
     e.g., 'user.name' -> 'user-2ename' (. = ASCII 46 = 0x2e)
     """
     from escapism import escape
-    return escape(username, escape_char='-')
+    return escape(username, escape_char='-').lower()
 
 
 class ManageVolumesHandler(BaseHandler):