diff --git a/sncf.ss b/sncf.ss
index 122e7ad..fe6a095 100755
--- a/sncf.ss
+++ b/sncf.ss
@@ -122,10 +122,13 @@
   (unless (null? disruptions)
     (displayln "Perturbations :"))
   (for ((dis disruptions))
-    (if (eq? style 'markdown)
-      (display "* ")
-      (display "• "))
-    (displayln (hash-ref (car (hash-ref dis 'messages)) 'text))))
+    (let ((messages (hash-ref dis 'messages '())))
+      (if (eq? style 'markdown)
+	(display "* ")
+	(display "• "))
+      (if (null? messages)
+	(displayln "[Pas de message]")
+	(displayln (hash-ref (car messages) 'text))))))
 
 (def (post-to-mattermost url text channel: (channel #f))
   (def data (list->hash-table `((text . ,text))))