diff --git a/moment-timezone/moment-timezone-tests.ts b/moment-timezone/moment-timezone-tests.ts
index b7624b63ad..d2cee664d0 100644
--- a/moment-timezone/moment-timezone-tests.ts
+++ b/moment-timezone/moment-timezone-tests.ts
@@ -75,3 +75,5 @@ moment.tz.load({
 });
 
 moment.tz.names();
+
+moment.tz.setDefault('America/Los_Angeles');
diff --git a/moment-timezone/moment-timezone.d.ts b/moment-timezone/moment-timezone.d.ts
index 2ac4730578..5e1ea09be0 100644
--- a/moment-timezone/moment-timezone.d.ts
+++ b/moment-timezone/moment-timezone.d.ts
@@ -68,6 +68,8 @@ interface MomentTimezone {
     }): void;
 
     names(): string[];
+
+    setDefault(timezone: string): void;
 }
 
 declare module 'moment-timezone' {