diff --git a/lib/Tools/java_monitor b/lib/Tools/java_monitor
--- a/lib/Tools/java_monitor
+++ b/lib/Tools/java_monitor
@@ -1,9 +1,7 @@
 #!/usr/bin/env bash
 #
 # Author: Makarius
 #
 # DESCRIPTION: monitor another Java process
 
-isabelle_admin_build jars || exit $?
-
 isabelle java isabelle.Java_Monitor "$@"