diff --git a/caddyconfig/httpcaddyfile/httptype.go b/caddyconfig/httpcaddyfile/httptype.go
index 2a11f85e5..ff52dbf9f 100644
--- a/caddyconfig/httpcaddyfile/httptype.go
+++ b/caddyconfig/httpcaddyfile/httptype.go
@@ -113,6 +113,7 @@ func (st ServerType) Setup(inputServerBlocks []caddyfile.ServerBlock,
 		"{tls_client_serial}", "{http.request.tls.client.serial}",
 		"{tls_client_subject}", "{http.request.tls.client.subject}",
 		"{tls_client_certificate_pem}", "{http.request.tls.client.certificate_pem}",
+		"{upstream_hostport}", "{http.reverse_proxy.upstream.hostport}",
 	)
 
 	// these are placeholders that allow a user-defined final