diff --git a/packages/playwright/src/matchers/expect.ts b/packages/playwright/src/matchers/expect.ts
index 21431d1eb1..ea796bfc72 100644
--- a/packages/playwright/src/matchers/expect.ts
+++ b/packages/playwright/src/matchers/expect.ts
@@ -289,8 +289,7 @@ class ExpectMetaInfoProxyHandler implements ProxyHandler<any> {
 
       const step = testInfo._addStep(stepInfo);
 
-      const reportStepError = (unknownError: unknown) => {
-        const jestError = unknownError instanceof Error ? unknownError : new Error(String(unknownError));
+      const reportStepError = (jestError: Error | unknown) => {
         const error = isExpectError(jestError) ? new ExpectError(jestError, customMessage, stackFrames) : jestError;
         step.complete({ error });
         if (this._info.isSoft)
diff --git a/packages/playwright/src/worker/testInfo.ts b/packages/playwright/src/worker/testInfo.ts
index b94da22bd9..e9d570bb20 100644
--- a/packages/playwright/src/worker/testInfo.ts
+++ b/packages/playwright/src/worker/testInfo.ts
@@ -30,7 +30,7 @@ import type { Attachment } from './testTracing';
 import type { StackFrame } from '@protocol/channels';
 
 export interface TestStepInternal {
-  complete(result: { error?: Error, attachments?: Attachment[] }): void;
+  complete(result: { error?: Error | unknown, attachments?: Attachment[] }): void;
   stepId: string;
   title: string;
   category: 'hook' | 'fixture' | 'test.step' | 'expect' | 'attach' | string;
@@ -267,7 +267,7 @@ export class TestInfoImpl implements TestInfo {
 
         step.endWallTime = Date.now();
         if (result.error) {
-          if (!(result.error as any)[stepSymbol])
+          if (typeof result.error === 'object' && !(result.error as any)?.[stepSymbol])
             (result.error as any)[stepSymbol] = step;
           const error = serializeError(result.error);
           if (data.boxedStack)
@@ -324,13 +324,13 @@ export class TestInfoImpl implements TestInfo {
       this.status = 'interrupted';
   }
 
-  _failWithError(error: Error) {
+  _failWithError(error: Error | unknown) {
     if (this.status === 'passed' || this.status === 'skipped')
       this.status = error instanceof TimeoutManagerError ? 'timedOut' : 'failed';
     const serialized = serializeError(error);
-    const step = (error as any)[stepSymbol] as TestStepInternal | undefined;
+    const step: TestStepInternal | undefined = typeof error === 'object' ? (error as any)?.[stepSymbol] : undefined;
     if (step && step.boxedStack)
-      serialized.stack = `${error.name}: ${error.message}\n${stringifyStackFrames(step.boxedStack).join('\n')}`;
+      serialized.stack = `${(error as Error).name}: ${(error as Error).message}\n${stringifyStackFrames(step.boxedStack).join('\n')}`;
     this.errors.push(serialized);
     this._tracing.appendForError(serialized);
   }
diff --git a/tests/playwright-test/expect-poll.spec.ts b/tests/playwright-test/expect-poll.spec.ts
index 00e19bc6f7..fb7f63e846 100644
--- a/tests/playwright-test/expect-poll.spec.ts
+++ b/tests/playwright-test/expect-poll.spec.ts
@@ -243,5 +243,5 @@ test('should propagate promise rejections', { annotation: { type: 'issue', descr
     `
   });
 
-  expect(result.output).toContain('Error: some error');
+  expect(result.output).toContain('some error');
 });
\ No newline at end of file