diff --git a/devel/schemata b/devel/schemata
index 8fcab8e5..f7e1b69f 100644
--- a/devel/schemata
+++ b/devel/schemata
@@ -32,7 +32,7 @@ thread = [thread_node*]
 
 # A message and its replies (show_messages)
 thread_node = [
-    message?,                 # null if not matched and not --entire-thread
+    message|null,             # null if not matched and not --entire-thread
     [thread_node*]            # children of message
 ]