diff --git a/meta/classes/uboot-config.bbclass b/meta/classes/uboot-config.bbclass
index 09a0c0f7b5..ba01bffa5f 100644
--- a/meta/classes/uboot-config.bbclass
+++ b/meta/classes/uboot-config.bbclass
@@ -47,7 +47,8 @@ python () {
             bb.debug(1, "Setting UBOOT_MACHINE to %s." % items[0])
             d.setVar('UBOOT_MACHINE', items[0])
 
-            if items[1]:
+            # IMAGE_FSTYPES appending
+            if len(items) > 1 and items[1]:
                 bb.debug(1, "Appending '%s' to IMAGE_FSTYPES." % items[1])
                 d.appendVar('IMAGE_FSTYPES', ' ' + items[1])
 }