diff --git a/syntax/ats.vim b/syntax/ats.vim
index 22a9409..0f39225 100644
--- a/syntax/ats.vim
+++ b/syntax/ats.vim
@@ -35,7 +35,7 @@ syn region atsArrow start="-<" end=">"
 
 syn keyword atsType void bool string char int uint uint8 uint32 uint16 int8 int32 int16 charNZ strnptr Strptr0 Strptr1 nat lint ulint double float size_t
 syn keyword atsType datavtype datatype vtypedef dataviewtype viewtypdef typedef view viewdef dataview abstype absvtype absviewtype absview datasort dataprop type viewtype vtype
-syn keyword atsType absimpl
+syn keyword atsType absimpl absprop
 syn keyword atsType implement primplmnt extern
 
 syn match atsParens "[()]"