diff --git a/paper-dropdown-menu-light.html b/paper-dropdown-menu-light.html
index edaabf8..13fab4b 100644
--- a/paper-dropdown-menu-light.html
+++ b/paper-dropdown-menu-light.html
@@ -366,6 +366,13 @@
             type: String
           },
 
+          /**
+           * The error message to display when invalid.
+           */
+          errorMessage: {
+              type: String
+          },
+
           /**
            * True if the dropdown is open. Otherwise, false.
            */