diff --git a/hive-c0re/src/gateway_nginx.rs b/hive-c0re/src/gateway_nginx.rs
index ba54f8f5..b759dd07 100644
--- a/hive-c0re/src/gateway_nginx.rs
+++ b/hive-c0re/src/gateway_nginx.rs
@@ -42,11 +42,13 @@ fn health() -> &'static Mutex<SweepHealth> {
 }
 
 /// Nginx proxy headers present in every per-agent location block.
-/// `$connection_upgrade` is defined in the http context by the NixOS
-/// nginx module when `recommendedProxySettings = true` (which the
-/// gateway always sets). `X-Forwarded-Prefix` is per-location (set
-/// below in the render loop). Kept as a standalone const so it's
-/// visible to tests without repeating the text.
+/// `$connection_upgrade` is an http-context variable the NixOS nginx
+/// module emits unconditionally (`map $http_upgrade $connection_upgrade`
+/// in `commonHttpConfig`); it does not depend on
+/// `recommendedProxySettings`, which several hyperhive vhosts turn off
+/// per location. `X-Forwarded-Prefix` is per-location (set below in the
+/// render loop). Kept as a standalone const so it's visible to tests
+/// without repeating the text.
 const PROXY_HEADER_BLOCK: &str = "    proxy_http_version 1.1;
     proxy_set_header Upgrade $http_upgrade;
     proxy_set_header Connection $connection_upgrade;