diff --git a/crates/zed/src/languages/php/highlights.scm b/crates/zed/src/languages/php/highlights.scm
index fcb087c47d..5f366b53c3 100644
--- a/crates/zed/src/languages/php/highlights.scm
+++ b/crates/zed/src/languages/php/highlights.scm
@@ -96,6 +96,7 @@
 "endwhile" @keyword
 "extends" @keyword
 "final" @keyword
+"readonly" @keyword
 "finally" @keyword
 "foreach" @keyword
 "function" @keyword