diff --git a/src/bucket.ts b/src/bucket.ts
index b251192d7..14b081842 100644
--- a/src/bucket.ts
+++ b/src/bucket.ts
@@ -31,7 +31,7 @@ import * as fs from 'fs';
 import * as http from 'http';
 import * as mime from 'mime-types';
 import * as path from 'path';
-import pLimit = require('p-limit');
+import * as pLimit from 'p-limit';
 import {promisify} from 'util';
 import retry = require('async-retry');
 import {convertObjKeysToSnakeCase} from './util';
@@ -309,7 +309,7 @@ export interface BucketMetadata extends BaseMetadata {
     };
   };
   labels?: {
-    [key: string]: string;
+    [key: string]: string | null;
   };
   lifecycle?: {
     rule?: LifecycleRule[];
diff --git a/system-test/storage.ts b/system-test/storage.ts
index ad56a902d..3cf0b3950 100644
--- a/system-test/storage.ts
+++ b/system-test/storage.ts
@@ -18,7 +18,7 @@ import * as crypto from 'crypto';
 import * as fs from 'fs';
 import fetch from 'node-fetch';
 import * as FormData from 'form-data';
-import pLimit = require('p-limit');
+import * as pLimit from 'p-limit';
 import {promisify} from 'util';
 import * as path from 'path';
 import * as tmp from 'tmp';
@@ -1108,7 +1108,7 @@ describe('storage', () => {
 
       it('should be available from updating a bucket', async () => {
         await bucket.setMetadata({labels: {a: 'b'}});
-        assert(types.includes(bucket.metadata.locationType));
+        assert(types.includes(bucket.metadata.locationType!));
       });
     });