diff -r de62440762b8 -r 6b8107df1c3a src/Pure/Isar/isar_syn.ML
--- a/src/Pure/Isar/isar_syn.ML	Wed Apr 05 21:08:24 2000 +0200
+++ b/src/Pure/Isar/isar_syn.ML	Thu Apr 06 13:39:49 2000 +0200
@@ -612,7 +612,7 @@
     (Scan.succeed IsarCmd.init_toplevel);
 
 val welcomeP =
-  OuterSyntax.improper_command "welcome" "print welcome message" K.control
+  OuterSyntax.improper_command "welcome" "print welcome message" K.diag
     (Scan.succeed IsarCmd.welcome);