diff --git a/lib/twiml/TwiML.ts b/lib/twiml/TwiML.ts
index 0148281483..e6d79957e2 100644
--- a/lib/twiml/TwiML.ts
+++ b/lib/twiml/TwiML.ts
@@ -7,6 +7,7 @@ import builder from "xmlbuilder";
 /* jshint ignore:end */
 
 export default class TwiML {
+  [key: string]: any;
   response: any;
   _propertyName: string;
 
@@ -35,7 +36,6 @@ export default class TwiML {
    */
   /* jshint ignore:end */
   _getXml() {
-    // @ts-ignore
     return this[this._propertyName];
   }
 
diff --git a/package.json b/package.json
index 4095ebd250..4b993ce327 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,7 @@
     "typedoc": "^0.23.21"
   },
   "scripts": {
-    "test": "npm run test:javascript",
+    "test": "npm run test:javascript && npm run test:typescript",
     "test:javascript": "jest spec/* --coverage --detectOpenHandles",
     "test:typescript": "tsc --noEmit",
     "jshint": "jshint lib/rest/** lib/base/** lib/http/**",