diff --git a/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala b/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
index 33851d9145..b2ed91256f 100644
--- a/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/LocalSparkCluster.scala
@@ -63,8 +63,11 @@ class LocalSparkCluster(
 
     /* Start the Workers */
     for (workerNum <- 1 to numWorkers) {
+      val workDir = if (Utils.isTesting) {
+        Utils.createTempDir(namePrefix = "worker").getAbsolutePath
+      } else null
       val workerEnv = Worker.startRpcEnvAndEndpoint(localHostname, 0, 0, coresPerWorker,
-        memoryPerWorker, masters, null, Some(workerNum), _conf,
+        memoryPerWorker, masters, workDir, Some(workerNum), _conf,
         conf.get(config.Worker.SPARK_WORKER_RESOURCE_FILE))
       workerRpcEnvs += workerEnv
     }