diff --git a/nginx.tmpl b/nginx.tmpl
index 6df80f6..e79f790 100644
--- a/nginx.tmpl
+++ b/nginx.tmpl
@@ -3,6 +3,7 @@
 {{ $external_http_port := coalesce $.Env.HTTP_PORT "80" }}
 {{ $external_https_port := coalesce $.Env.HTTPS_PORT "443" }}
 {{ $debug_all := $.Env.DEBUG }}
+{{ $sha1_upstream_name := parseBool (coalesce $.Env.SHA1_UPSTREAM_NAME "false") }}
 
 {{ define "ssl_policy" }}
 	{{ if eq .ssl_policy "Mozilla-Modern" }}
@@ -153,7 +154,8 @@ server {
 {{ range $host, $containers := groupByMulti $ "Env.VIRTUAL_HOST" "," }}
 
 {{ $host := trim $host }}
-{{ $upstream_name := sha1 $host }}
+{{ $is_regexp := hasPrefix "~" $host }}
+{{ $upstream_name := when (or $is_regexp $sha1_upstream_name) (sha1 $host) $host }}
 
 # {{ $host }}
 upstream {{ $upstream_name }} {