diff --git a/app.json b/app.json
index 2ab1f0281..181d34eda 100644
--- a/app.json
+++ b/app.json
@@ -24,9 +24,13 @@
       "description": "Where this website will be running (probably <app name>.herokuapp.com)"
     },
     "PUBLIC_PORT": {
-      "description": "HTTPS port number on PUBLIC_HOST",
+      "description": "Port number on PUBLIC_HOST",
       "value": "443"
     },
+    "PUBLIC_PROTOCOL": {
+      "description": "Protocol to use when connecting to PUBLIC_HOST:PUBLIC_PORT",
+      "value": "https"
+    },
     "SECRET_KEY_BASE": {
       "description": "A secret key for verifying the integrity of cookies",
       "generator": "secret"
diff --git a/config/prod.secret.exs b/config/prod.secret.exs
index 25a36f03c..df94632d9 100644
--- a/config/prod.secret.exs
+++ b/config/prod.secret.exs
@@ -11,7 +11,7 @@ config :bors, BorsNG.Endpoint,
   http: [port: {:system, "PORT"}],
   url: [
     host: {:system, "PUBLIC_HOST"},
-    scheme: "https",
+    scheme: {:system, "PUBLIC_PROTOCOL", "https"},
     port: {:system, :integer, "PUBLIC_PORT", 443}
   ],
   check_origin: false,