diff --git a/after/syntax/css/css3-regions.vim b/after/syntax/css/css3-regions.vim
index 9ea8fc0..59a36af 100644
--- a/after/syntax/css/css3-regions.vim
+++ b/after/syntax/css/css3-regions.vim
@@ -1,6 +1,7 @@
-" TODO: create cssRegionsProp group and cssRegionsAttr group
-syn match cssFontProp contained "\<flow-\(from\|into\)\>"
-syn match cssFontProp contained "\<region-fragment\>"
-syn keyword cssFontAttr contained element content break
-syn match cssFontAttr contained "\<\(avoid-\)\=region\>"
-syn region cssPseudoClassLang matchgroup=cssPseudoClassId start="::\=region(" end=")" oneline
+if !hlexists('cssRegionsProp')
+  syn match cssFontProp contained "\<flow-\(into\|from\)\>"
+  syn match cssFontProp contained "\<region-fragment\>"
+  syn keyword cssFontAttr contained element content break
+  syn match cssFontAttr contained "\<\(avoid-\)\=region\>"
+  syn keyword cssPseudoClassId contained region
+endif
diff --git a/test/test.css b/test/test.css
index a928e9c..8c646d1 100644
--- a/test/test.css
+++ b/test/test.css
@@ -306,13 +306,12 @@
   presentation-level: increment;
 }
 
-.regions:region(p),
-.regions::region(p) {
-  flow-from: break;
-  flow-into: region;
-  region-fragment: avoid-region;
-  display: element;
-  display: content;
+.regions:region {
+  flow-into: element;
+  flow-from: content;
+  region-fragment: break;
+  display: region;
+  display: avoid-region;
 }
 
 .ruby {
diff --git a/test/test.html b/test/test.html
index 1f45cf3..feeed44 100644
--- a/test/test.html
+++ b/test/test.html
@@ -316,13 +316,12 @@
         presentation-level: increment;
       }
 
-      .regions:region(p),
-      .regions::region(p) {
-        flow-from: break;
-        flow-into: region;
-        region-fragment: avoid-region;
-        display: element;
-        display: content;
+      .regions:region {
+        flow-into: element;
+        flow-from: content;
+        region-fragment: break;
+        display: region;
+        display: avoid-region;
       }
 
       .ruby {