diff --git a/core/Makefile b/core/Makefile
index c98df0c..ae1bf57 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -521,14 +521,14 @@
 $(INSTALLED_BOOTIMAGE_TARGET): $(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_FILES) $(VBOOT_SIGNER)
 	$(call pretty,"Target boot image: $@")
 	$(hide) $(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_ARGS) $(BOARD_MKBOOTIMG_ARGS) --output $@.unsigned
-	$(VBOOT_SIGNER) $(FUTILITY) $@.unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $@.keyblock $@
+	$(VBOOT_SIGNER) $(FUTILITY) $@.unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_SUBKEY).vbprivk $@.keyblock $@
 	$(hide) $(call assert-max-image-size,$@,$(BOARD_BOOTIMAGE_PARTITION_SIZE))
 
 .PHONY: bootimage-nodeps
 bootimage-nodeps: $(MKBOOTIMG) $(VBOOT_SIGNER)
 	@echo "make $@: ignoring dependencies"
 	$(hide) $(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_ARGS) $(BOARD_MKBOOTIMG_ARGS) --output $(INSTALLED_BOOTIMAGE_TARGET).unsigned
-	$(VBOOT_SIGNER) $(FUTILITY) $(INSTALLED_BOOTIMAGE_TARGET).unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $(INSTALLED_BOOTIMAGE_TARGET).keyblock $(INSTALLED_BOOTIMAGE_TARGET)
+	$(VBOOT_SIGNER) $(FUTILITY) $(INSTALLED_BOOTIMAGE_TARGET).unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_SUBKEY).vbprivk $(INSTALLED_BOOTIMAGE_TARGET).keyblock $(INSTALLED_BOOTIMAGE_TARGET)
 	$(hide) $(call assert-max-image-size,$(INSTALLED_BOOTIMAGE_TARGET),$(BOARD_BOOTIMAGE_PARTITION_SIZE))
 
 else # PRODUCT_SUPPORTS_VBOOT != true
@@ -755,6 +755,7 @@
 $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VENDOR_VERITY_PARTITION),$(hide) echo "vendor_verity_block_device=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VENDOR_VERITY_PARTITION)" >> $(1))
 $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT)" >> $(1))
 $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_key=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY)" >> $(1))
+$(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_subkey=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_SUBKEY)" >> $(1))
 $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "futility=$(FUTILITY)" >> $(1))
 $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_signer_cmd=$(VBOOT_SIGNER)" >> $(1))
 $(if $(filter true,$(BOARD_BUILD_SYSTEM_ROOT_IMAGE)),\
@@ -891,7 +892,7 @@
   $(if $(filter true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_BOOT_SIGNER)),\
     $(BOOT_SIGNER) /recovery $(1) $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY).pk8 $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY).x509.pem $(1))
   $(if $(filter true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT)), \
-    $(VBOOT_SIGNER) $(FUTILITY) $(1).unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $(1).keyblock $(1))
+    $(VBOOT_SIGNER) $(FUTILITY) $(1).unsigned $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbpubk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_KEY).vbprivk $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_SUBKEY).vbprivk $(1).keyblock $(1))
   $(hide) $(call assert-max-image-size,$(1),$(BOARD_RECOVERYIMAGE_PARTITION_SIZE))
   @echo ----- Made recovery image: $(1) --------
 endef
diff --git a/core/product.mk b/core/product.mk
index 4e8bff1..e97cba4 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -104,6 +104,7 @@
     PRODUCT_SYSTEM_PROPERTY_BLACKLIST \
     PRODUCT_SYSTEM_SERVER_JARS \
     PRODUCT_VBOOT_SIGNING_KEY \
+    PRODUCT_VBOOT_SIGNING_SUBKEY \
     PRODUCT_VERITY_SIGNING_KEY \
     PRODUCT_SYSTEM_VERITY_PARTITION \
     PRODUCT_VENDOR_VERITY_PARTITION \
diff --git a/target/product/vboot.mk b/target/product/vboot.mk
index e4b1144..48a4883 100644
--- a/target/product/vboot.mk
+++ b/target/product/vboot.mk
@@ -22,3 +22,4 @@
 # We expect this file to exist with the suffixes ".vbprivk" and ".vbpupk".
 # TODO: find a proper location for this
 PRODUCT_VBOOT_SIGNING_KEY := external/vboot_reference/tests/devkeys/kernel_data_key
+PRODUCT_VBOOT_SIGNING_SUBKEY := external/vboot_reference/tests/devkeys/kernel_subkey