diff --git a/CHANGELOG.md b/CHANGELOG.md
index 50237a17f7e2..5f7b0d20d544 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Fixes
 
 - `[jest-haste-map]` Add missing `@types/graceful-fs` dependency ([#9913](https://github.com/facebook/jest/pull/9913))
+- `[jest-runner]` Correctly serialize `Set` passed to worker ([#9915](https://github.com/facebook/jest/pull/9915))
 
 ### Chore & Maintenance
 
diff --git a/packages/jest-runner/src/index.ts b/packages/jest-runner/src/index.ts
index 9cf5659426cb..0f1d069c6af0 100644
--- a/packages/jest-runner/src/index.ts
+++ b/packages/jest-runner/src/index.ts
@@ -158,6 +158,9 @@ class TestRunner {
             changedFiles:
               this._context.changedFiles &&
               Array.from(this._context.changedFiles),
+            sourcesRelatedToTestsInChangedFiles:
+              this._context.sourcesRelatedToTestsInChangedFiles &&
+              Array.from(this._context.sourcesRelatedToTestsInChangedFiles),
           },
           globalConfig: this._globalConfig,
           path: test.path,
diff --git a/packages/jest-runner/src/testWorker.ts b/packages/jest-runner/src/testWorker.ts
index b7a3dcf858ff..70d45328a4ab 100644
--- a/packages/jest-runner/src/testWorker.ts
+++ b/packages/jest-runner/src/testWorker.ts
@@ -89,6 +89,9 @@ export async function worker({
       context && {
         ...context,
         changedFiles: context.changedFiles && new Set(context.changedFiles),
+        sourcesRelatedToTestsInChangedFiles:
+          context.sourcesRelatedToTestsInChangedFiles &&
+          new Set(context.sourcesRelatedToTestsInChangedFiles),
       },
     );
   } catch (error) {
diff --git a/packages/jest-runner/src/types.ts b/packages/jest-runner/src/types.ts
index 4862c886ce86..c4fc43117ff0 100644
--- a/packages/jest-runner/src/types.ts
+++ b/packages/jest-runner/src/types.ts
@@ -49,6 +49,7 @@ export type TestRunnerOptions = {
   serial: boolean;
 };
 
+// make sure all props here are present in the type below it as well
 export type TestRunnerContext = {
   changedFiles?: Set<Config.Path>;
   sourcesRelatedToTestsInChangedFiles?: Set<Config.Path>;
@@ -56,6 +57,7 @@ export type TestRunnerContext = {
 
 export type TestRunnerSerializedContext = {
   changedFiles?: Array<Config.Path>;
+  sourcesRelatedToTestsInChangedFiles?: Array<Config.Path>;
 };
 
 // TODO: Should live in `@jest/core` or `jest-watcher`