diff --git a/conf/nginx.conf b/conf/nginx.conf
index acc2c5c..440d241 100644
--- a/conf/nginx.conf
+++ b/conf/nginx.conf
@@ -8,6 +8,7 @@ location __PATH__/ {
   proxy_set_header Upgrade $http_upgrade;
   proxy_set_header Connection upgrade;
 
+  # Must be at least as large as the chunk size of PsiTransfer.
   client_max_body_size 5M;
 
   # Include SSOWAT user panel.