diff --git a/lib/services/caldav-sync.ts b/lib/services/caldav-sync.ts
index 27708e3..01ad4db 100644
--- a/lib/services/caldav-sync.ts
+++ b/lib/services/caldav-sync.ts
@@ -98,9 +98,17 @@ export async function discoverInfomaniakCalendars(
 
     return calendars;
   } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    const errorDetails = error instanceof Error ? {
+      name: error.name,
+      message: error.message,
+      stack: error.stack?.substring(0, 200), // First 200 chars of stack
+    } : { raw: String(error) };
+    
     logger.error('Error discovering Infomaniak calendars', {
       email,
-      error: error instanceof Error ? error.message : String(error),
+      error: errorMessage,
+      errorDetails,
     });
     // Ne pas faire échouer toute la page agenda si la découverte échoue
     // On retourne simplement une liste vide -> pas de sync auto possible
diff --git a/lib/services/microsoft-oauth.ts b/lib/services/microsoft-oauth.ts
index 877f716..ad148f9 100644
--- a/lib/services/microsoft-oauth.ts
+++ b/lib/services/microsoft-oauth.ts
@@ -51,7 +51,8 @@ export async function exchangeCodeForTokens(code: string): Promise<{
     client_secret: clientSecret!,
     code,
     redirect_uri: redirectUri!,
-    grant_type: 'authorization_code'
+    grant_type: 'authorization_code',
+    scope: REQUIRED_SCOPES // Include scopes in token exchange
   });
 
   try {