diff --git a/integration-tests/test-helper.ts b/integration-tests/test-helper.ts
index 00cf77de4c..c772cd6603 100644
--- a/integration-tests/test-helper.ts
+++ b/integration-tests/test-helper.ts
@@ -270,13 +270,13 @@ export class TestRig {
       child.stdin!.write(execOptions.input);
     }
 
-    if (
+    const keepStdinOpen =
       typeof promptOrOptions === 'object' &&
-      !promptOrOptions.stdinDoesNotEnd
-    ) {
+      promptOrOptions !== null &&
+      promptOrOptions.stdinDoesNotEnd === true;
+    if (!keepStdinOpen) {
       child.stdin!.end();
     }
-    child.stdin!.end();
 
     child.stdout!.on('data', (data: Buffer) => {
       stdout += data;