diff --git a/after/syntax/css/display-4.vim b/after/syntax/css/display-4.vim
index 43e07f5..2f7edb8 100644
--- a/after/syntax/css/display-4.vim
+++ b/after/syntax/css/display-4.vim
@@ -1,2 +1,2 @@
-syn keyword cssFontProp contained reading-flow
-syn keyword cssFontAttr contained flex-visual flex-flow grid-rows grid-columns
+syn keyword cssFontProp contained reading-flow reading-order
+syn keyword cssFontAttr contained flex-visual flex-flow grid-rows grid-columns source-order force-hidden
diff --git a/test/test.css b/test/test.css
index 5ec2e66..62212ae 100644
--- a/test/test.css
+++ b/test/test.css
@@ -397,10 +397,13 @@
 
 .display-4 {
   reading-flow: auto;
+  reading-order: auto;
   display: flex-visual;
   display: flex-flow;
   display: grid-rows;
   display: grid-columns;
+  display: source-order;
+  display: force-hidden;
 }
 
 .easing-1 {