diff --git a/packages/cloudflare/src/transport.ts b/packages/cloudflare/src/transport.ts
index 40b8549df9cd..108a0e915656 100644
--- a/packages/cloudflare/src/transport.ts
+++ b/packages/cloudflare/src/transport.ts
@@ -1,5 +1,5 @@
 import type { BaseTransportOptions, Transport, TransportMakeRequestResponse, TransportRequest } from '@sentry/core';
-import { SentryError, createTransport, suppressTracing } from '@sentry/core';
+import { SENTRY_BUFFER_FULL_ERROR, createTransport, suppressTracing } from '@sentry/core';
 
 export interface CloudflareTransportOptions extends BaseTransportOptions {
   /** Fetch API init parameters. */
@@ -38,7 +38,7 @@ export class IsolatedPromiseBuffer {
    */
   public add(taskProducer: () => PromiseLike<TransportMakeRequestResponse>): PromiseLike<TransportMakeRequestResponse> {
     if (this._taskProducers.length >= this._bufferSize) {
-      return Promise.reject(new SentryError('Not adding Promise because buffer limit was reached.'));
+      return Promise.reject(SENTRY_BUFFER_FULL_ERROR);
     }
 
     this._taskProducers.push(taskProducer);
diff --git a/packages/cloudflare/test/transport.test.ts b/packages/cloudflare/test/transport.test.ts
index d3aca638eba1..d02ef18079be 100644
--- a/packages/cloudflare/test/transport.test.ts
+++ b/packages/cloudflare/test/transport.test.ts
@@ -1,4 +1,4 @@
-import { createEnvelope, serializeEnvelope } from '@sentry/core';
+import { SENTRY_BUFFER_FULL_ERROR, createEnvelope, serializeEnvelope } from '@sentry/core';
 import type { EventEnvelope, EventItem } from '@sentry/core';
 import { afterAll, describe, expect, it, vi } from 'vitest';
 
@@ -140,7 +140,12 @@ describe('IsolatedPromiseBuffer', () => {
     await ipb.add(task2);
     await ipb.add(task3);
 
-    await expect(ipb.add(task4)).rejects.toThrowError('Not adding Promise because buffer limit was reached.');
+    try {
+      await ipb.add(task4);
+      throw new Error('Should not be called');
+    } catch (error) {
+      expect(error).toBe(SENTRY_BUFFER_FULL_ERROR);
+    }
   });
 
   it('should not throw when one of the tasks throws when drained', async () => {
diff --git a/packages/core/src/transports/base.ts b/packages/core/src/transports/base.ts
index 9296095428cf..2b7de82ba4e1 100644
--- a/packages/core/src/transports/base.ts
+++ b/packages/core/src/transports/base.ts
@@ -14,9 +14,8 @@ import {
   forEachEnvelopeItem,
   serializeEnvelope,
 } from '../utils-hoist/envelope';
-import { SentryError } from '../utils-hoist/error';
 import { logger } from '../utils-hoist/logger';
-import { type PromiseBuffer, makePromiseBuffer } from '../utils-hoist/promisebuffer';
+import { type PromiseBuffer, makePromiseBuffer, SENTRY_BUFFER_FULL_ERROR } from '../utils-hoist/promisebuffer';
 import { type RateLimits, isRateLimited, updateRateLimits } from '../utils-hoist/ratelimit';
 import { resolvedSyncPromise } from '../utils-hoist/syncpromise';
 
@@ -85,7 +84,7 @@ export function createTransport(
     return buffer.add(requestTask).then(
       result => result,
       error => {
-        if (error instanceof SentryError) {
+        if (error === SENTRY_BUFFER_FULL_ERROR) {
           DEBUG_BUILD && logger.error('Skipped sending event because buffer is full.');
           recordEnvelopeLoss('queue_overflow');
           return resolvedSyncPromise({});
diff --git a/packages/core/src/utils-hoist/index.ts b/packages/core/src/utils-hoist/index.ts
index 4f22928eff86..88801545f3d5 100644
--- a/packages/core/src/utils-hoist/index.ts
+++ b/packages/core/src/utils-hoist/index.ts
@@ -53,7 +53,7 @@ export {
   objectify,
 } from './object';
 export { basename, dirname, isAbsolute, join, normalizePath, relative, resolve } from './path';
-export { makePromiseBuffer } from './promisebuffer';
+export { makePromiseBuffer, SENTRY_BUFFER_FULL_ERROR } from './promisebuffer';
 export type { PromiseBuffer } from './promisebuffer';
 
 export { severityLevelFromString } from './severity';
diff --git a/packages/core/src/utils-hoist/promisebuffer.ts b/packages/core/src/utils-hoist/promisebuffer.ts
index 32b90e4d8519..d7eb82443fda 100644
--- a/packages/core/src/utils-hoist/promisebuffer.ts
+++ b/packages/core/src/utils-hoist/promisebuffer.ts
@@ -1,4 +1,3 @@
-import { SentryError } from './error';
 import { SyncPromise, rejectedSyncPromise, resolvedSyncPromise } from './syncpromise';
 
 export interface PromiseBuffer<T> {
@@ -9,6 +8,8 @@ export interface PromiseBuffer<T> {
   drain(timeout?: number): PromiseLike<boolean>;
 }
 
+export const SENTRY_BUFFER_FULL_ERROR = Symbol.for('SentryBufferFullError');
+
 /**
  * Creates an new PromiseBuffer object with the specified limit
  * @param limit max number of promises that can be stored in the buffer
@@ -42,7 +43,7 @@ export function makePromiseBuffer<T>(limit?: number): PromiseBuffer<T> {
    */
   function add(taskProducer: () => PromiseLike<T>): PromiseLike<T> {
     if (!isReady()) {
-      return rejectedSyncPromise(new SentryError('Not adding Promise because buffer limit was reached.'));
+      return rejectedSyncPromise(SENTRY_BUFFER_FULL_ERROR);
     }
 
     // start the task and add its promise to the queue
diff --git a/packages/vercel-edge/src/transports/index.ts b/packages/vercel-edge/src/transports/index.ts
index e938477b3003..e1ce24c501c7 100644
--- a/packages/vercel-edge/src/transports/index.ts
+++ b/packages/vercel-edge/src/transports/index.ts
@@ -1,5 +1,5 @@
 import type { BaseTransportOptions, Transport, TransportMakeRequestResponse, TransportRequest } from '@sentry/core';
-import { SentryError, createTransport, suppressTracing } from '@sentry/core';
+import { SENTRY_BUFFER_FULL_ERROR, createTransport, suppressTracing } from '@sentry/core';
 
 export interface VercelEdgeTransportOptions extends BaseTransportOptions {
   /** Fetch API init parameters. */
@@ -38,7 +38,7 @@ export class IsolatedPromiseBuffer {
    */
   public add(taskProducer: () => PromiseLike<TransportMakeRequestResponse>): PromiseLike<TransportMakeRequestResponse> {
     if (this._taskProducers.length >= this._bufferSize) {
-      return Promise.reject(new SentryError('Not adding Promise because buffer limit was reached.'));
+      return Promise.reject(SENTRY_BUFFER_FULL_ERROR);
     }
 
     this._taskProducers.push(taskProducer);
diff --git a/packages/vercel-edge/test/transports/index.test.ts b/packages/vercel-edge/test/transports/index.test.ts
index 4434a177d0f8..a7e6bd342fb5 100644
--- a/packages/vercel-edge/test/transports/index.test.ts
+++ b/packages/vercel-edge/test/transports/index.test.ts
@@ -1,6 +1,6 @@
 import { afterAll, describe, expect, it, vi } from 'vitest';
 
-import { createEnvelope, serializeEnvelope } from '@sentry/core';
+import { SENTRY_BUFFER_FULL_ERROR, createEnvelope, serializeEnvelope } from '@sentry/core';
 import type { EventEnvelope, EventItem } from '@sentry/core';
 
 import type { VercelEdgeTransportOptions } from '../../src/transports';
@@ -139,7 +139,12 @@ describe('IsolatedPromiseBuffer', () => {
     await ipb.add(task2);
     await ipb.add(task3);
 
-    await expect(ipb.add(task4)).rejects.toThrowError('Not adding Promise because buffer limit was reached.');
+    try {
+      await ipb.add(task4);
+      throw new Error('Should not be called');
+    } catch (error) {
+      expect(error).toBe(SENTRY_BUFFER_FULL_ERROR);
+    }
   });
 
   it('should not throw when one of the tasks throws when drained', async () => {