diff -r 9fc965612459 -r bcdecd466cb2 src/Pure/System/isabelle_tool.scala
--- a/src/Pure/System/isabelle_tool.scala	Sun Jan 01 23:08:39 2017 +0100
+++ b/src/Pure/System/isabelle_tool.scala	Sun Jan 01 23:19:34 2017 +0100
@@ -114,6 +114,7 @@
       Update_Header.isabelle_tool,
       Update_Then.isabelle_tool,
       Update_Theorems.isabelle_tool,
+      isabelle.vscode.Grammar.isabelle_tool,
       isabelle.vscode.Server.isabelle_tool)
 
   private def list_internal(): List[(String, String)] =