diff --git a/languages/csharp/highlights.scm b/languages/csharp/highlights.scm
index c47b285..2f9581f 100644
--- a/languages/csharp/highlights.scm
+++ b/languages/csharp/highlights.scm
@@ -223,6 +223,20 @@
   "let"
 ] @keyword
 
+; pattern expression keywords
+(negated_pattern
+  "not" @keyword)
+
+(and_pattern
+  "and" @keyword)
+
+(or_pattern
+  "or" @keyword)
+
+; scoped keyword
+(scoped_type
+  "scoped" @keyword)
+
 ; Attribute
 (attribute
   name: (identifier) @attribute)