diff --git a/src/KeyringController.test.ts b/src/KeyringController.test.ts
index 67fd436b..e4e1efc7 100644
--- a/src/KeyringController.test.ts
+++ b/src/KeyringController.test.ts
@@ -122,7 +122,8 @@ describe('KeyringController', () => {
       await keyringController.persistAllKeyrings();
 
       const { vault } = keyringController.store.getState();
-      const keyrings = await mockEncryptor.decrypt(PASSWORD, vault as string);
+      assert(vault, "Vault is not set");
+      const keyrings = await mockEncryptor.decrypt(PASSWORD, vault);
       expect(keyrings).toContain(unsupportedKeyring);
       expect(keyrings).toHaveLength(2);
     });