diff --git a/metropolis/test/launch/cluster/cluster.go b/metropolis/test/launch/cluster/cluster.go
index 9b32f97..bd3a76a 100644
--- a/metropolis/test/launch/cluster/cluster.go
+++ b/metropolis/test/launch/cluster/cluster.go
@@ -380,7 +380,7 @@
 	go func() {
 		if err := launch.RunMicroVM(ctxT, &launch.MicroVMOptions{
 			KernelPath:             "metropolis/test/ktest/vmlinux",
-			InitramfsPath:          "metropolis/test/nanoswitch/initramfs.lz4",
+			InitramfsPath:          "metropolis/test/nanoswitch/initramfs.cpio.lz4",
 			ExtraNetworkInterfaces: switchPorts,
 			PortMap:                portMap,
 		}); err != nil {