diff --git a/moment-timezone/moment-timezone-tests.ts b/moment-timezone/moment-timezone-tests.ts
index 410c45fe2e..5ce57818c1 100644
--- a/moment-timezone/moment-timezone-tests.ts
+++ b/moment-timezone/moment-timezone-tests.ts
@@ -80,7 +80,7 @@ moment.tz.setDefault('America/Los_Angeles');
 
 moment.tz.guess();
 
-moment.tz('America/Los_Angeles').zoneAbbr();
+var zoneAbbr: string = moment.tz('America/Los_Angeles').zoneAbbr();
 
-moment.tz('America/Los_Angeles').zoneName();
+var zoneName: string = moment.tz('America/Los_Angeles').zoneName();