diff --git a/lib/ace/mode/dart_highlight_rules.js b/lib/ace/mode/dart_highlight_rules.js
index 08055502..ea49ca70 100644
--- a/lib/ace/mode/dart_highlight_rules.js
+++ b/lib/ace/mode/dart_highlight_rules.js
@@ -13,7 +13,7 @@ var DartHighlightRules = function() {
     var constantLanguage = "true|false|null";
     var variableLanguage = "this|super";
     var keywordControl = "try|catch|finally|throw|break|case|continue|default|do|else|for|if|in|return|switch|while|new";
-    var keywordDeclaration = "abstract|class|extends|external|factory|implements|get|native|operator|set|typedef";
+    var keywordDeclaration = "abstract|class|extends|external|factory|implements|get|native|operator|set|typedef|with";
     var storageModifier = "static|final|const";
     var storageType = "void|bool|num|int|double|dynamic|var|String";