Update runtime files
diff --git a/runtime/syntax/mupad.vim b/runtime/syntax/mupad.vim
index 55ea9c4..df87ad1 100644
--- a/runtime/syntax/mupad.vim
+++ b/runtime/syntax/mupad.vim
@@ -279,5 +279,6 @@
 hi def link mupadDefine		Define
 hi def link mupadIdentifier	Identifier
 
+let b:current_syntax = 'mupad'
 
 " TODO  More comprehensive listing.