diff --git a/syntax/ats.vim b/syntax/ats.vim
index 6f5bf1f..ba473b0 100644
--- a/syntax/ats.vim
+++ b/syntax/ats.vim
@@ -18,7 +18,7 @@ syn match atsSpecial -\v\\[0-9]+-
 
 syn region atsString start=+"+ end=+"+ contains=atsSpecial
 
-syn keyword atsKeyword staload dynload overload with fun symintr include fn fnx and prfun prfn
+syn keyword atsKeyword staload dynload overload with fun symintr include fn fnx and prfun prfn praxi
 syn keyword atsKeyword lam llam fix raise of var val prval if then else
 syn keyword atsKeywordTwo case ifcase