diff --git a/loader.js b/loader.js
index f5793e8aff..3071a6f8d5 100644
--- a/loader.js
+++ b/loader.js
@@ -115,7 +115,7 @@ function forkWorker(index, isPrimary) {
 	}
 
 	process.env.isPrimary = isPrimary;
-	process.env.isCluster = ports.length > 1;
+	process.env.isCluster = nconf.get('isCluster') || ports.length > 1;
 	process.env.port = ports[index];
 
 	var worker = fork(appPath, args, {