diff --git a/target/image/x86/Makefile b/target/image/x86/Makefile
index dfafe4241f..fd424ffd00 100644
--- a/target/image/x86/Makefile
+++ b/target/image/x86/Makefile
@@ -17,11 +17,11 @@ ifeq ($(CONFIG_X86_GRUB_IMAGES),y)
   endef
 
   define Image/cmdline/jffs2-64k
-    block2mtd.block2mtd=/dev/hda2,65536 root=/dev/mtdblock0 rootfstype=jffs2
+    block2mtd.block2mtd=$(CONFIG_X86_GRUB_ROOTPART),65536 root=/dev/mtdblock0 rootfstype=jffs2
   endef
 
   define Image/cmdline/jffs2-128k
-    block2mtd.block2mtd=/dev/hda2,131072 root=/dev/mtdblock0 rootfstype=jffs2
+    block2mtd.block2mtd=$(CONFIG_X86_GRUB_ROOTPART),131072 root=/dev/mtdblock0 rootfstype=jffs2
   endef
 
   define Image/cmdline/ext2