diff --git a/target/linux/ramips/image/Makefile b/target/linux/ramips/image/Makefile
index 8ab8aa3a6c..cd77ffe411 100644
--- a/target/linux/ramips/image/Makefile
+++ b/target/linux/ramips/image/Makefile
@@ -31,7 +31,7 @@ loadaddr-$(CONFIG_TARGET_ramips_mt7621) := 0x80001000
 
 KERNEL_LOADADDR := $(loadaddr-y)
 
-KERNEL_DTB = kernel-bin | patch-dtb | lzma
+KERNEL_DTB = kernel-bin | patch-dtb | lzma -d21
 define Device/Default
   PROFILES = Default $$(DTS)
   KERNEL_DEPENDS = $$(wildcard ../dts/$$(DTS).dts)