diff --git a/Makefile b/Makefile
index 40885e4..6737a4f 100644
--- a/Makefile
+++ b/Makefile
@@ -216,7 +216,7 @@ qemu: fs.img xv6.img
 	$(QEMU) -serial mon:stdio $(QEMUOPTS)
 
 qemu-memfs: xv6memfs.img
-	$(QEMU) xv6memfs.img -smp $(CPUS) -m 256
+	$(QEMU) -drive file=xv6memfs.img,index=0,media=disk,format=raw -smp $(CPUS) -m 256
 
 qemu-nox: fs.img xv6.img
 	$(QEMU) -nographic $(QEMUOPTS)