diff --git a/packages/playwright/src/reporters/json.ts b/packages/playwright/src/reporters/json.ts
index db40750d36..d6833dba02 100644
--- a/packages/playwright/src/reporters/json.ts
+++ b/packages/playwright/src/reporters/json.ts
@@ -203,6 +203,7 @@ class JSONReporter implements ReporterV2 {
     const steps = result.steps.filter(s => s.category === 'test.step');
     const jsonResult: JSONReportTestResult = {
       workerIndex: result.workerIndex,
+      parallelIndex: result.parallelIndex,
       status: result.status,
       duration: result.duration,
       error: result.error,
diff --git a/packages/playwright/types/testReporter.d.ts b/packages/playwright/types/testReporter.d.ts
index 9662faee73..2abfa9592e 100644
--- a/packages/playwright/types/testReporter.d.ts
+++ b/packages/playwright/types/testReporter.d.ts
@@ -291,6 +291,7 @@ export interface JSONReportError {
 
 export interface JSONReportTestResult {
   workerIndex: number;
+  parallelIndex: number;
   status: TestStatus | undefined;
   duration: number;
   error: TestError | undefined;