diff --git a/IDL.tmLanguage b/IDL.tmLanguage
index 5e43598..ebd424f 100644
--- a/IDL.tmLanguage
+++ b/IDL.tmLanguage
@@ -454,7 +454,7 @@
 		<!-- class definition -->
 		<dict>
 			<key>begin</key>
-			<string>\b(coclass|dispinterface|library|struct|interface|enum)\s+([_A-Za-z][_A-Za-z0-9]*\b)</string>
+			<string>\b(coclass|dispinterface|library|struct|interface|enum|dictionary)\s+([_A-Za-z][_A-Za-z0-9]*\b)(?:\s*:\s*([_A-Za-z][_A-Za-z0-9]*\b))?</string>
 			<key>beginCaptures</key>
 			<dict>
 				<key>1</key>
@@ -467,6 +467,11 @@
 					<key>name</key>
 					<string>entity.name.type.webidl</string>
 				</dict>
+				<key>3</key>
+				<dict>
+					<key>name</key>
+					<string>entity.other.inherited-class.webidl</string>
+				</dict>
 			</dict>
 			<key>end</key>
 			<string>([_A-Za-z][_A-Za-z0-9]*\b)? (?&lt;=\})|(?=(;|,|\(|\)|&gt;|\[|\]))</string>