diff --git a/dev-packages/cloudflare-integration-tests/runner.ts b/dev-packages/cloudflare-integration-tests/runner.ts
index e0a48dd33ff5..542ffe82b802 100644
--- a/dev-packages/cloudflare-integration-tests/runner.ts
+++ b/dev-packages/cloudflare-integration-tests/runner.ts
@@ -50,6 +50,12 @@ type StartResult = {
     path: string,
     options?: { headers?: Record<string, string>; data?: BodyInit; expectError?: boolean },
   ): Promise<T | undefined>;
+  makeRequestAndWaitForEnvelope<T>(
+    method: 'get' | 'post',
+    path: string,
+    expected: Expected | Expected[],
+    options?: { headers?: Record<string, string>; data?: BodyInit; expectError?: boolean },
+  ): Promise<T | undefined>;
 };
 
 /** Creates a test runner */
@@ -108,6 +114,7 @@ export function createRunner(...paths: string[]) {
       const expectedEnvelopeCount = expectedEnvelopes.length;
 
       let envelopeCount = 0;
+      const envelopeWaiters: { expected: Expected; resolve: () => void; reject: (e: unknown) => void }[] = [];
       const { resolve: setWorkerPort, promise: workerPortPromise } = deferredPromise<number>();
       let child: ReturnType<typeof spawn> | undefined;
       let childSubWorker: ReturnType<typeof spawn> | undefined;
@@ -120,6 +127,12 @@ export function createRunner(...paths: string[]) {
         }
       }
 
+      function waitForEnvelope(expected: Expected): Promise<void> {
+        return new Promise((resolveWaiter, rejectWaiter) => {
+          envelopeWaiters.push({ expected, resolve: resolveWaiter, reject: rejectWaiter });
+        });
+      }
+
       function assertEnvelopeMatches(expected: Expected, envelope: Envelope): void {
         if (typeof expected === 'function') {
           expected(envelope);
@@ -137,6 +150,18 @@ export function createRunner(...paths: string[]) {
           return;
         }
 
+        // Check per-request waiters first (FIFO order)
+        if (envelopeWaiters.length > 0) {
+          const waiter = envelopeWaiters.shift()!;
+          try {
+            assertEnvelopeMatches(waiter.expected, envelope);
+            waiter.resolve();
+          } catch (e) {
+            waiter.reject(e);
+          }
+          return;
+        }
+
         try {
           if (unordered) {
             // find any matching expected envelope
@@ -242,6 +267,10 @@ export function createRunner(...paths: string[]) {
               `SENTRY_DSN:http://public@localhost:${mockServerPort}/1337`,
               '--var',
               `SERVER_URL:${serverUrl}`,
+              '--port',
+              '0',
+              '--inspector-port',
+              '0',
               ...extraWranglerArgs,
             ],
             { stdio, signal },
@@ -304,6 +333,18 @@ export function createRunner(...paths: string[]) {
             return;
           }
         },
+        makeRequestAndWaitForEnvelope: async function <T>(
+          method: 'get' | 'post',
+          path: string,
+          expected: Expected | Expected[],
+          options: { headers?: Record<string, string>; data?: BodyInit; expectError?: boolean } = {},
+        ): Promise<T | undefined> {
+          const expectations = Array.isArray(expected) ? expected : [expected];
+          const envelopePromises = expectations.map(e => waitForEnvelope(e));
+          const result = await this.makeRequest<T>(method, path, options);
+          await Promise.all(envelopePromises);
+          return result;
+        },
       };
     },
   };
diff --git a/dev-packages/cloudflare-integration-tests/suites/public-api/startSpan-streamed/test.ts b/dev-packages/cloudflare-integration-tests/suites/public-api/startSpan-streamed/test.ts
index 090142714d5b..d9c18431202b 100644
--- a/dev-packages/cloudflare-integration-tests/suites/public-api/startSpan-streamed/test.ts
+++ b/dev-packages/cloudflare-integration-tests/suites/public-api/startSpan-streamed/test.ts
@@ -197,7 +197,7 @@ it('sends a streamed span envelope with correct spans for a manually started spa
           },
           'url.port': {
             type: 'string',
-            value: '8787',
+            value: expect.stringMatching(/^\d{4,5}$/),
           },
           'url.scheme': {
             type: 'string',
@@ -221,7 +221,7 @@ it('sends a streamed span envelope with correct spans for a manually started spa
           },
           'http.request.header.cf_connecting_ip': {
             type: 'string',
-            value: '::1',
+            value: expect.stringMatching(/^(::1|127\.0\.0\.1)$/),
           },
           'http.request.header.host': {
             type: 'string',
diff --git a/dev-packages/cloudflare-integration-tests/suites/tracing/durableobject-spans/test.ts b/dev-packages/cloudflare-integration-tests/suites/tracing/durableobject-spans/test.ts
index 1415950208cc..483b170936e4 100644
--- a/dev-packages/cloudflare-integration-tests/suites/tracing/durableobject-spans/test.ts
+++ b/dev-packages/cloudflare-integration-tests/suites/tracing/durableobject-spans/test.ts
@@ -25,15 +25,13 @@ it.skip('sends child spans on repeated Durable Object calls', async ({ signal })
 
     // All 5 child spans should be present
     expect(transactionEvent.spans).toHaveLength(5);
-    expect(transactionEvent.spans).toEqual(
-      expect.arrayContaining([
-        expect.objectContaining({ description: 'task-1', op: 'task' }),
-        expect.objectContaining({ description: 'task-2', op: 'task' }),
-        expect.objectContaining({ description: 'task-3', op: 'task' }),
-        expect.objectContaining({ description: 'task-4', op: 'task' }),
-        expect.objectContaining({ description: 'task-5', op: 'task' }),
-      ]),
-    );
+    expect(transactionEvent.spans).toEqual([
+      expect.objectContaining({ description: 'task-1', op: 'task' }),
+      expect.objectContaining({ description: 'task-2', op: 'task' }),
+      expect.objectContaining({ description: 'task-3', op: 'task' }),
+      expect.objectContaining({ description: 'task-4', op: 'task' }),
+      expect.objectContaining({ description: 'task-5', op: 'task' }),
+    ]);
 
     // All child spans share the root trace_id
     const rootTraceId = transactionEvent.contexts?.trace?.trace_id;
@@ -43,13 +41,12 @@ it.skip('sends child spans on repeated Durable Object calls', async ({ signal })
     }
   }
 
-  // Expect 5 transaction envelopes — one per call.
-  const runner = createRunner(__dirname).expectN(5, assertDoWorkEnvelope).start(signal);
+  const runner = createRunner(__dirname).start(signal);
 
-  await runner.makeRequest('get', '/');
-  await runner.makeRequest('get', '/');
-  await runner.makeRequest('get', '/');
-  await runner.makeRequest('get', '/');
-  await runner.makeRequest('get', '/');
-  await runner.completed();
+  // Each request waits for its envelope to be received and validated before proceeding.
+  await runner.makeRequestAndWaitForEnvelope('get', '/', assertDoWorkEnvelope);
+  await runner.makeRequestAndWaitForEnvelope('get', '/', assertDoWorkEnvelope);
+  await runner.makeRequestAndWaitForEnvelope('get', '/', assertDoWorkEnvelope);
+  await runner.makeRequestAndWaitForEnvelope('get', '/', assertDoWorkEnvelope);
+  await runner.makeRequestAndWaitForEnvelope('get', '/', assertDoWorkEnvelope);
 });
diff --git a/dev-packages/cloudflare-integration-tests/vite.config.mts b/dev-packages/cloudflare-integration-tests/vite.config.mts
index a80bbbf63f32..0fdb560b8f11 100644
--- a/dev-packages/cloudflare-integration-tests/vite.config.mts
+++ b/dev-packages/cloudflare-integration-tests/vite.config.mts
@@ -28,6 +28,9 @@ export default defineConfig({
         singleThread: true,
       },
     },
+    sequence: {
+      shuffle: true,
+    },
     reporters: process.env.DEBUG
       ? ['default', { summary: false }]
       : process.env.GITHUB_ACTIONS