diff --git a/core/nginx/letsencrypt.py b/core/nginx/letsencrypt.py
index edf24430..4c139d36 100755
--- a/core/nginx/letsencrypt.py
+++ b/core/nginx/letsencrypt.py
@@ -61,7 +61,7 @@ def serve_one_request():
 # Run certbot every day
 while True:
     while True:
-        hostname = os.environ['HOSTNAMES'].split(' ')[0]
+        hostname = os.environ['HOSTNAMES'].split(',')[0]
         target = f'http://{hostname}/.well-known/acme-challenge/testing'
         thread = Thread(target=serve_one_request)
         thread.start()
diff --git a/towncrier/newsfragments/2990.misc b/towncrier/newsfragments/2990.misc
new file mode 100644
index 00000000..6d122e90
--- /dev/null
+++ b/towncrier/newsfragments/2990.misc
@@ -0,0 +1 @@
+Fix letsencrypt