diff --git a/config/runtime.exs b/config/runtime.exs
index ee17f01..deb386d 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -52,7 +52,7 @@ if config_env() == :prod do
       You can generate one by calling: mix phx.gen.secret
       """
 
-  host = System.get_env("RENDER_EXTERNAL_HOSTNAME") || "example.com"
+  host = System.get_env("PHX_HOSTNAME") || "example.com"
   port = String.to_integer(System.get_env("PORT") || "4000")
 
   config :flick, :dns_cluster_query, System.get_env("DNS_CLUSTER_QUERY")