diff --git a/packages/cloudflare/test/executionContext.test-d.ts b/packages/cloudflare/test/executionContext.test-d.ts
new file mode 100644
index 000000000000..77ec388beb03
--- /dev/null
+++ b/packages/cloudflare/test/executionContext.test-d.ts
@@ -0,0 +1,28 @@
+import type { ExecutionContext } from '@cloudflare/workers-types';
+import { describe, expectTypeOf, it } from 'vitest';
+import type { ExecutionContextCompat } from '../src/executionContext';
+
+// The shape of `ExecutionContext` in `@cloudflare/workers-types` v4, which has no `exports` and an optional `tracing`.
+interface ExecutionContextV4 {
+  waitUntil(promise: Promise<unknown>): void;
+  passThroughOnException(): void;
+  readonly props: unknown;
+}
+
+describe('ExecutionContextCompat', () => {
+  it('accepts a v5 ExecutionContext', () => {
+    expectTypeOf<ExecutionContext>().toExtend<ExecutionContextCompat>();
+  });
+
+  it('accepts a v4 ExecutionContext without the members v5 made required', () => {
+    expectTypeOf<ExecutionContextV4>().toExtend<ExecutionContextCompat>();
+  });
+
+  it('rejects a context without waitUntil', () => {
+    expectTypeOf<Omit<ExecutionContextV4, 'waitUntil'>>().not.toExtend<ExecutionContextCompat>();
+  });
+
+  it('exposes waitUntil from both majors', () => {
+    expectTypeOf<ExecutionContextCompat['waitUntil']>().toEqualTypeOf<ExecutionContext['waitUntil']>();
+  });
+});
diff --git a/packages/cloudflare/test/withSentry.test.ts b/packages/cloudflare/test/withSentry.test.ts
new file mode 100644
index 000000000000..c2282ba1f72b
--- /dev/null
+++ b/packages/cloudflare/test/withSentry.test.ts
@@ -0,0 +1,73 @@
+import type { ExecutionContext } from '@cloudflare/workers-types';
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { withSentry } from '../src/withSentry';
+import { resetSdk } from './testUtils';
+
+const MOCK_ENV = {
+  SENTRY_DSN: 'https://public@dsn.ingest.sentry.io/1337',
+};
+
+function createMockExecutionContext(): ExecutionContext {
+  return {
+    waitUntil: vi.fn(),
+    passThroughOnException: vi.fn(),
+    props: {},
+  } as unknown as ExecutionContext;
+}
+
+class WorkerEntrypoint {
+  public constructor(
+    public ctx: ExecutionContext,
+    public env: unknown,
+  ) {}
+}
+
+describe('withSentry', () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+    resetSdk();
+  });
+
+  it('returns the same handler object with its methods wrapped', () => {
+    const fetch = vi.fn();
+    const handler = { fetch };
+
+    const wrapped = withSentry(() => ({}), handler);
+
+    expect(wrapped).toBe(handler);
+    expect(wrapped.fetch).not.toBe(fetch);
+  });
+
+  it('instruments a WorkerEntrypoint class instead of treating it as a handler object', () => {
+    class MyEntrypoint extends WorkerEntrypoint {
+      public ping(): string {
+        return 'pong';
+      }
+    }
+
+    const optionsCallback = vi.fn().mockReturnValue({ dsn: MOCK_ENV.SENTRY_DSN });
+    const context = createMockExecutionContext();
+
+    const Wrapped = withSentry(optionsCallback, MyEntrypoint as never) as unknown as typeof MyEntrypoint;
+    const instance = new Wrapped(context, MOCK_ENV);
+
+    expect(Wrapped).not.toBe(MyEntrypoint);
+    expect(optionsCallback).toHaveBeenCalledWith(MOCK_ENV);
+    expect(instance).toBeInstanceOf(MyEntrypoint);
+    expect(instance.ctx).not.toBe(context);
+    expect(instance.ping()).toBe('pong');
+  });
+
+  it('returns a handler it cannot instrument unchanged instead of throwing', () => {
+    const fetch = vi.fn();
+    const handler = Object.freeze({ fetch });
+
+    let wrapped: typeof handler | undefined;
+    expect(() => {
+      wrapped = withSentry(() => ({}), handler);
+    }).not.toThrow();
+
+    expect(wrapped).toBe(handler);
+    expect(wrapped?.fetch).toBe(fetch);
+  });
+});