diff --git a/src/Cmi5.ts b/src/Cmi5.ts
index 1149709..6ef4f56 100644
--- a/src/Cmi5.ts
+++ b/src/Cmi5.ts
@@ -50,6 +50,6 @@ export default class Cmi5 extends AbstractCmi5 {
   protected static getLaunchParametersFromLMS(): LaunchParameters {
     return XAPI.getSearchQueryParamsAsObject(
       window.location.search
-    ) as LaunchParameters;
+    ) as unknown as LaunchParameters;
   }
 }