diff --git a/externs/bootstrap.js b/externs/bootstrap.js
index 401e609fcd..442377e4ca 100644
--- a/externs/bootstrap.js
+++ b/externs/bootstrap.js
@@ -8,14 +8,14 @@
 
 
 /**
- * @param {String|Object.<string,*>=} option
+ * @param {string|Object.<string,*>=} option
  * @return {!jQuery}
  */
 jQuery.prototype.popover = function(option) {};
 
 
 /**
- * @param {String|Object.<string,*>=} option
+ * @param {string|Object.<string,*>=} option
  * @return {!jQuery}
  */
 jQuery.prototype.tooltip = function(option) {};