diff --git a/cmd/git-bundle-web-server/bundle-server.go b/cmd/git-bundle-web-server/bundle-server.go
index b495f1a..8e03eed 100644
--- a/cmd/git-bundle-web-server/bundle-server.go
+++ b/cmd/git-bundle-web-server/bundle-server.go
@@ -185,6 +185,16 @@ func (b *bundleWebServer) StartServerAsync(ctx context.Context) {
 		}
 	}(ctx)
 
+	// Wait 0.1s before reporting that the server is started in case
+	// 'listenAndServeFunc' exits immediately.
+	//
+	// It's a hack, but a necessary one because 'ListenAndServe[TLS]()' doesn't
+	// have any mechanism of notifying if it starts successfully, only that it
+	// fails. We could get around that by copying/reimplementing those functions
+	// with a print statement inserted at the right place, but that's way more
+	// cumbersome than just adding a delay here (see:
+	// https://stackoverflow.com/questions/53332667/how-to-notify-when-http-server-starts-successfully).
+	time.Sleep(time.Millisecond * 100)
 	fmt.Println("Server is running at address " + b.server.Addr)
 }
 
diff --git a/test/shared/classes/bundleServer.ts b/test/shared/classes/bundleServer.ts
index 90aa36b..94ccef0 100644
--- a/test/shared/classes/bundleServer.ts
+++ b/test/shared/classes/bundleServer.ts
@@ -21,12 +21,38 @@ export class BundleServer {
     this.bundleWebServerCmd = bundleWebServerCmd
   }
 
-  startWebServer(port: number): void {
+  async startWebServer(port: number): Promise<void> {
     if (this.webServerProcess) {
       throw new Error("Tried to start web server, but web server is already running")
     }
-    this.webServerProcess = child_process.spawn(this.bundleWebServerCmd, ["--port", String(port)])
+    const webServerProcess = child_process.spawn(this.bundleWebServerCmd, ["--port", String(port)])
+    this.webServerProcess = webServerProcess
     this.bundleUriBase = `http://localhost:${port}/`
+
+    // Now, ensure the server is running
+    var timer: NodeJS.Timeout | undefined
+    var ok: boolean | undefined
+
+    await Promise.race([
+      new Promise<void>(resolve => webServerProcess.stdout.on('data', (data: string) => {
+        if (data.includes("Server is running at address") && ok === undefined) {
+          ok = true
+          resolve() // server is running
+        }
+      })),
+      new Promise<void>(resolve => webServerProcess.on('close', () => {
+        ok = false
+        resolve() // program failed to start/exited early
+      })),
+      new Promise(resolve => timer = setTimeout(resolve, 2000)) // fallback timeout
+    ])
+
+    // If it's still running, clear the timeout so it doesn't delay shutdown
+    clearTimeout(timer)
+
+    if (!ok) {
+      throw new Error('Failed to start web server')
+    }
   }
 
   init(remote: RemoteRepo, routePrefix: string, route: string = ""): child_process.SpawnSyncReturns<Buffer> {
diff --git a/test/shared/features/step_definitions/bundleServer.ts b/test/shared/features/step_definitions/bundleServer.ts
index 5d1cc26..220e5b8 100644
--- a/test/shared/features/step_definitions/bundleServer.ts
+++ b/test/shared/features/step_definitions/bundleServer.ts
@@ -2,5 +2,5 @@ import { Given } from '@cucumber/cucumber'
 import { BundleServerWorldBase } from '../../support/world'
 
 Given('the bundle web server was started at port {int}', async function (this: BundleServerWorldBase, port: number) {
-  this.bundleServer.startWebServer(port)
+  await this.bundleServer.startWebServer(port)
 })