diff --git a/src/App.jsx b/src/App.jsx
index 1eff2a7..e79ee89 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -24,6 +24,8 @@ import frenchMessages from "./i18n/fr";
 import chineseMessages from "./i18n/zh";
 import italianMessages from "./i18n/it";
 
+const fixed_base_url = undefined; // FIXME: process.env.REACT_APP_SERVER;
+
 // TODO: Can we use lazy loading together with browser locale?
 const messages = {
   de: germanMessages,
@@ -42,7 +44,7 @@ const App = () => (
     disableTelemetry
     requireAuth
     loginPage={LoginPage}
-    authProvider={authProvider}
+    authProvider={authProvider(fixed_base_url)}
     dataProvider={dataProvider}
     i18nProvider={i18nProvider}
   >
diff --git a/src/components/LoginPage.jsx b/src/components/LoginPage.jsx
index b81109e..3209003 100644
--- a/src/components/LoginPage.jsx
+++ b/src/components/LoginPage.jsx
@@ -81,7 +81,7 @@ const FormBox = styled(Box)(({ theme }) => ({
   },
 }));
 
-const LoginPage = () => {
+const LoginPage = ({ cfg_base_url }) => {
   const login = useLogin();
   const notify = useNotify();
   const [loading, setLoading] = useState(false);
@@ -89,7 +89,6 @@ const LoginPage = () => {
   const [locale, setLocale] = useLocaleState();
   const translate = useTranslate();
   const base_url = localStorage.getItem("base_url");
-  const cfg_base_url = process.env.REACT_APP_SERVER;
   const [ssoBaseUrl, setSSOBaseUrl] = useState("");
   const loginToken = /\?loginToken=([a-zA-Z0-9_-]+)/.exec(window.location.href);
 
@@ -247,7 +246,7 @@ const LoginPage = () => {
             name="base_url"
             component={renderInput}
             label="synapseadmin.auth.base_url"
-            disabled={cfg_base_url || loading}
+            disabled={cfg_base_url != null || loading}
             resettable
             fullWidth
             className="input"
diff --git a/src/synapse/authProvider.js b/src/synapse/authProvider.js
index 723f155..38e5071 100644
--- a/src/synapse/authProvider.js
+++ b/src/synapse/authProvider.js
@@ -1,10 +1,10 @@
 import { fetchUtils } from "react-admin";
 
-const authProvider = {
+const authProvider = fixed_base_url => ({
   // called when the user attempts to log in
   login: ({ base_url, username, password, loginToken }) => {
     // force homeserver for protection in case the form is manipulated
-    base_url = process.env.REACT_APP_SERVER || base_url;
+    base_url = fixed_base_url || base_url;
 
     console.log("login ");
     const options = {
@@ -86,6 +86,6 @@ const authProvider = {
   },
   // called when the user navigates to a new location, to check for permissions / roles
   getPermissions: () => Promise.resolve(),
-};
+});
 
 export default authProvider;