diff --git a/ui/styling/styling.d.ts b/ui/styling/styling.d.ts
index 280111f2f..0bf3ebb67 100644
--- a/ui/styling/styling.d.ts
+++ b/ui/styling/styling.d.ts
@@ -92,6 +92,11 @@
          * Gets or sets font-size style property.
          */
         fontSize: number;
+        
+        /**
+         * Gets or sets z-index style property.
+         */        
+        zIndex: number;
 
         /**
          * Gets or sets font-family style property.