diff --git a/mode/php/php.js b/mode/php/php.js
index e112d91121c3e80ca7337f239281a2c87e81b53f..1c62eb485a6c9311a04a19c6afaf2ee7e40cd6cf 100644
--- a/mode/php/php.js
+++ b/mode/php/php.js
@@ -94,6 +94,7 @@
     helperType: "php",
     keywords: keywords(phpKeywords),
     blockKeywords: keywords("catch do else elseif for foreach if switch try while finally"),
+    defKeywords: keywords("class function interface namespace trait"),
     atoms: keywords(phpAtoms),
     builtin: keywords(phpBuiltin),
     multiLineStrings: true,