diff --git a/runtime/queries/c_sharp/highlights.scm b/runtime/queries/c_sharp/highlights.scm
index d8cf08388..0c9489506 100644
--- a/runtime/queries/c_sharp/highlights.scm
+++ b/runtime/queries/c_sharp/highlights.scm
@@ -90,6 +90,9 @@
 (parameter
   name: (identifier) @variable.parameter)
 
+(parameter
+  (modifier) @keyword.modifier)
+
 (parameter_list
   name: (identifier) @variable.parameter)