diff --git a/apps/transport/lib/transport_web/endpoint.ex b/apps/transport/lib/transport_web/endpoint.ex
index 37c3e11afc..afdf20bb9c 100644
--- a/apps/transport/lib/transport_web/endpoint.ex
+++ b/apps/transport/lib/transport_web/endpoint.ex
@@ -61,19 +61,4 @@ defmodule TransportWeb.Endpoint do
   plug(Plug.Session, @session_options)
 
   plug(TransportWeb.Plugs.Router)
-
-  @doc """
-  Callback invoked for dynamically configuring the endpoint.
-
-  It receives the endpoint configuration and checks if
-  configuration should be loaded from the system environment.
-  """
-  def init(_key, config) do
-    if config[:load_from_system_env] do
-      port = System.get_env("PORT") || raise "expected the PORT environment variable to be set"
-      {:ok, Keyword.put(config, :http, [:inet6, port: port])}
-    else
-      {:ok, config}
-    end
-  end
 end
diff --git a/config/prod.exs b/config/prod.exs
index 559ee16e0b..5e4fd11b1c 100644
--- a/config/prod.exs
+++ b/config/prod.exs
@@ -1,15 +1,5 @@
 import Config
 
-config :transport, TransportWeb.Endpoint,
-  http: [port: System.get_env("PORT"), compress: true],
-  url: [scheme: "https", host: System.get_env("DOMAIN_NAME", "transport.data.gouv.fr"), port: 443],
-  cache_static_manifest: "priv/static/cache_manifest.json",
-  secret_key_base: System.get_env("SECRET_KEY_BASE"),
-  force_ssl: [rewrite_on: [:x_forwarded_proto]],
-  live_view: [
-    signing_salt: System.get_env("SECRET_KEY_BASE")
-  ]
-
 config :transport,
   # The key used by Cloak. See `Transport.Vault`.
   # This value should be base64 encrypted
diff --git a/config/runtime.exs b/config/runtime.exs
index a21feb0607..38bd3cdb6f 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -223,6 +223,16 @@ if config_env() == :prod do
     # under "Queue config". For most users, configuring :timeout is enough, as it now includes both queue and query time
     timeout: 15_000
 
+  config :transport, TransportWeb.Endpoint,
+    http: [port: System.get_env("PORT"), compress: true],
+    url: [scheme: "https", host: System.get_env("DOMAIN_NAME"), port: 443],
+    cache_static_manifest: "priv/static/cache_manifest.json",
+    secret_key_base: System.get_env("SECRET_KEY_BASE"),
+    force_ssl: [rewrite_on: [:x_forwarded_proto]],
+    live_view: [
+      signing_salt: System.get_env("SECRET_KEY_BASE")
+    ]
+
   if app_env == :production do
     # data.gouv.fr IDs for national databases created automatically and
     # published by us on data.gouv.fr.