diff --git a/.vim.local/syntax/demo-srd.vim b/.vim.local/syntax/demo-srd.vim
index 84d7731..d8ed04e 100644
--- a/.vim.local/syntax/demo-srd.vim
+++ b/.vim.local/syntax/demo-srd.vim
@@ -7,7 +7,7 @@ syn sync lines=100
 " ------------------------------------------------------------------------------
 " Clusters
 
-syn cluster srdListCluster	contains=@srdListCluster,srdKWDefAsset,srdKWDebug,srdKWFlow,srdKWState,srdKWDraw,srdKWExpr,srdWord,srdVariable,srdSLComment,srdMLComment,srdString,srdNumeric,srdBinary
+syn cluster srdListCluster	contains=@srdListCluster,srdBuiltin,srdKWDefAsset,srdKWDebug,srdKWFlow,srdKWState,srdKWDraw,srdKWExpr,srdWord,srdVariable,srdSLComment,srdMLComment,srdString,srdNumeric,srdBinary
 syn cluster srdCommentCluster	contains=@srdCommentCluster,srdTodo
 
 " ------------------------------------------------------------------------------
@@ -52,6 +52,8 @@ syn keyword srdKWExpr		cmp-eq cmp-ne cmp-gt cmp-ge cmp-lt cmp-le
 syn keyword srdKWExpr		inv neg not sin cos tan sqrt ln exp
 syn keyword srdKWExpr		get-input
 
+syn keyword srdBuiltin		time $time width $width height $height
+
 " ------------------------------------------------------------------------------
 " Variables, words and numbers
 
@@ -85,6 +87,7 @@ hi def link srdTodo Todo
 hi def link srdWord Identifier
 
 hi def srdVariable ctermfg=121 cterm=italic
+hi def srdBuiltin ctermfg=121 cterm=bold
 hi def srdNumeric cterm=italic ctermfg=10
 hi def srdKWExpr ctermfg=39 cterm=italic