diff --git a/src/lib/updating-element.ts b/src/lib/updating-element.ts
index 2f642e64..047fbfd0 100644
--- a/src/lib/updating-element.ts
+++ b/src/lib/updating-element.ts
@@ -15,7 +15,7 @@
 /**
  * Converts property values to and from attribute values.
  */
-interface AttributeSerializer<T = any> {
+export interface AttributeSerializer<T = any> {
 
   /**
    * Deserializing function called to convert an attribute value to a property