diff --git a/packages/backend-openapi-utils/src/proxy/setup.ts b/packages/backend-openapi-utils/src/proxy/setup.ts
index ed35a0d3c5..0e47e4a5d6 100644
--- a/packages/backend-openapi-utils/src/proxy/setup.ts
+++ b/packages/backend-openapi-utils/src/proxy/setup.ts
@@ -58,14 +58,40 @@ export class Proxy {
     this.express.server = server;
   }
 
-  stop() {
+  async stop() {
     if (Object.keys(this.#openRequests).length > 0) {
       throw new Error('There are still open requests');
     }
-    this.server.stop();
+    if (!this.express.server) {
+      throw new Error(
+        'Proxy server was not initialized with an express server',
+      );
+    }
+    const results = await Promise.allSettled([
+      this.server.stop(),
 
-    // If this isn't expressly closed, it will cause a jest memory leak warning.
-    this.express.server?.close();
+      // If this isn't expressly closed, it will cause a jest memory leak warning.
+      new Promise((resolve, reject) => {
+        this.express.server?.close(err => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(undefined);
+          }
+        });
+      }),
+    ]);
+    if (results.some(result => result.status === 'rejected')) {
+      const errors = results
+        .filter(
+          (result): result is PromiseRejectedResult =>
+            result.status === 'rejected',
+        )
+        .map(result => result.reason);
+      throw new Error(
+        `Failed to stop proxy server: ${errors.map(e => e.message).join(', ')}`,
+      );
+    }
   }
 
   get url() {
diff --git a/packages/backend-openapi-utils/src/testUtils.ts b/packages/backend-openapi-utils/src/testUtils.ts
index 88bb3db5bf..afb431c75b 100644
--- a/packages/backend-openapi-utils/src/testUtils.ts
+++ b/packages/backend-openapi-utils/src/testUtils.ts
@@ -16,8 +16,9 @@
 import { Express } from 'express';
 import { Server } from 'node:http';
 import { Proxy } from './proxy/setup';
+import { randomUUID } from 'node:crypto';
 
-const proxiesToCleanup: Proxy[] = [];
+const proxiesToCleanup: Record<string, Proxy> = {};
 
 /**
  * !!! THIS CURRENTLY ONLY SUPPORTS SUPERTEST !!!
@@ -29,7 +30,8 @@ const proxiesToCleanup: Proxy[] = [];
  */
 export async function wrapServer(app: Express): Promise<Server> {
   const proxy = new Proxy();
-  proxiesToCleanup.push(proxy);
+  const proxyId = randomUUID();
+  proxiesToCleanup[proxyId] = proxy;
   await proxy.setup();
 
   const server = app.listen(proxy.forwardTo.port);
@@ -48,10 +50,11 @@ function registerHooks() {
   }
   registered = true;
 
-  afterAll(() => {
-    for (const proxy of proxiesToCleanup) {
-      proxy.stop();
-    }
+  afterAll(async () => {
+    const stopPromises = Object.entries(proxiesToCleanup).map(([key, proxy]) =>
+      proxy.stop().finally(() => delete proxiesToCleanup[key]),
+    );
+    await Promise.allSettled(stopPromises);
   });
 }