diff --git a/selectize/selectize.d.ts b/selectize/selectize.d.ts
index 3ac665458d..3a61334f56 100644
--- a/selectize/selectize.d.ts
+++ b/selectize/selectize.d.ts
@@ -183,6 +183,13 @@ declare module Selectize {
          */
         valueField?: string;
 
+        /**
+         * Option groups that options will be bucketed into.
+         * If your element is a <select> with <optgroup>s this property gets populated automatically.
+         * Make sure each object in the array has a property named whatever "optgroupValueField" is set to.
+         */
+        optgroups?: U[];
+
         /**
          * The name of the option group property that serves as its unique identifier.
          *