diff --git a/dunstrc b/dunstrc
index 37407c7..61f5540 100644
--- a/dunstrc
+++ b/dunstrc
@@ -173,7 +173,8 @@
 
     # Redisplay last message(s).
     # On the US keyboard layout "grave" is normally above TAB and left
-    # of "1".
+    # of "1". Make sure this key actually exists on your keyboard layout,
+    # e.g. check output of 'xmodmap -pke'
     history = ctrl+grave
 
     # Context menu.