diff --git a/config/runtime.exs b/config/runtime.exs
index 7facf39..1959c00 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -52,7 +52,7 @@ if config_env() == :prod do
   port = String.to_integer(System.get_env("PORT") || "4000")
 
   config :cal, CalWeb.Endpoint,
-    url: [host: host, port: 443, scheme: "https"],
+    url: [host: host, port: 443],
     http: [
       # Enable IPv6 and bind on all interfaces.
       # Set it to  {0, 0, 0, 0, 0, 0, 0, 1} for local network only access.