diff --git a/client/src/const.ts b/client/src/const.ts
index 9999063..335a171 100644
--- a/client/src/const.ts
+++ b/client/src/const.ts
@@ -4,6 +4,10 @@ export { COOKIE_NAME, ONE_YEAR_MS } from "@shared/const";
 export const getLoginUrl = () => {
   const oauthPortalUrl = import.meta.env.VITE_OAUTH_PORTAL_URL;
   const appId = import.meta.env.VITE_APP_ID;
+
+  // Si OAUTH_PORTAL_URL n'est pas configuré (déploiement sans OAuth Manus), retourner chaîne vide
+  if (!oauthPortalUrl) return "";
+
   const redirectUri = `${window.location.origin}/api/oauth/callback`;
   const state = btoa(redirectUri);
 
diff --git a/client/src/pages/Login.tsx b/client/src/pages/Login.tsx
index ab5eaa4..db5dbac 100644
--- a/client/src/pages/Login.tsx
+++ b/client/src/pages/Login.tsx
@@ -7,6 +7,8 @@ const SANTINOVA_LOGO_TEXT = "Santinova Soft";
 
 export default function Login() {
   const [, navigate] = useLocation();
+  const loginUrl = getLoginUrl();
+  const oauthEnabled = !!loginUrl;
 
   return (
     <div className="min-h-screen flex bg-background">
@@ -78,29 +80,33 @@ export default function Login() {
           </p>
 
           <div className="space-y-4">
-            {/* Connexion via espace adhérent FEHAP */}
-            <a
-              href={getLoginUrl()}
-              className="group flex items-center gap-4 p-5 bg-primary text-white rounded-2xl shadow-md hover:bg-primary/90 transition-all hover:shadow-lg hover:-translate-y-0.5"
-            >
-              <div className="w-10 h-10 rounded-xl bg-white/20 flex items-center justify-center flex-shrink-0">
-                <ExternalLink size={20} className="text-white" />
-              </div>
-              <div className="flex-1 text-left">
-                <div className="font-semibold text-base">Espace adhérent FEHAP</div>
-                <div className="text-sm text-white/75 mt-0.5">
-                  Connexion via votre compte FEHAP existant
+            {/* Connexion via espace adhérent FEHAP — masqué si OAuth non configuré */}
+            {oauthEnabled && (
+              <a
+                href={loginUrl}
+                className="group flex items-center gap-4 p-5 bg-primary text-white rounded-2xl shadow-md hover:bg-primary/90 transition-all hover:shadow-lg hover:-translate-y-0.5"
+              >
+                <div className="w-10 h-10 rounded-xl bg-white/20 flex items-center justify-center flex-shrink-0">
+                  <ExternalLink size={20} className="text-white" />
                 </div>
-              </div>
-              <span className="text-white/50 group-hover:text-white/80 transition-colors text-lg">→</span>
-            </a>
+                <div className="flex-1 text-left">
+                  <div className="font-semibold text-base">Espace adhérent FEHAP</div>
+                  <div className="text-sm text-white/75 mt-0.5">
+                    Connexion via votre compte FEHAP existant
+                  </div>
+                </div>
+                <span className="text-white/50 group-hover:text-white/80 transition-colors text-lg">→</span>
+              </a>
+            )}
 
-            {/* Séparateur */}
-            <div className="flex items-center gap-3 py-1">
-              <div className="flex-1 h-px bg-border" />
-              <span className="text-xs text-muted-foreground font-medium">ou</span>
-              <div className="flex-1 h-px bg-border" />
-            </div>
+            {/* Séparateur — affiché seulement si OAuth activé */}
+            {oauthEnabled && (
+              <div className="flex items-center gap-3 py-1">
+                <div className="flex-1 h-px bg-border" />
+                <span className="text-xs text-muted-foreground font-medium">ou</span>
+                <div className="flex-1 h-px bg-border" />
+              </div>
+            )}
 
             {/* Connexion locale */}
             <button