diff --git a/lib/process-manager.js b/lib/process-manager.js
index 1665f38430..e2885a1847 100644
--- a/lib/process-manager.js
+++ b/lib/process-manager.js
@@ -28,12 +28,12 @@ class SubprocessStream extends Streams.ObjectReadWriteStream {
 		this.process.send(`${taskId}\nNEW`);
 	}
 	_write(/** @type {string} */ message) {
-		if (!process.connected) return;
+		if (!this.process.connected) return;
 		this.process.send(`${this.taskId}\nWRITE\n${message}`);
 		// responses are handled in ProcessWrapper
 	}
 	_destroy() {
-		if (!process.connected) return;
+		if (!this.process.connected) return;
 		this.process.send(`${this.taskId}\nDESTROY`);
 	}
 }