diff --git a/test/nbrowser/testServer.ts b/test/nbrowser/testServer.ts
index 3b292768..417ad8dc 100644
--- a/test/nbrowser/testServer.ts
+++ b/test/nbrowser/testServer.ts
@@ -68,7 +68,7 @@ export class TestServerMerged extends EventEmitter implements IMochaServer {
     const workerIdText = process.env.MOCHA_WORKER_ID || '0';
     if (reset) {
       // Make sure this test server doesn't keep using the DB that's about to disappear.
-      this.closeDatabase();
+      await this.closeDatabase();
 
       if (process.env.TESTDIR) {
         this.testDir = path.join(process.env.TESTDIR, workerIdText);