diff --git a/src/ec/google/chromeec/Kconfig b/src/ec/google/chromeec/Kconfig
index 2e4affc975..0f0803c297 100644
--- a/src/ec/google/chromeec/Kconfig
+++ b/src/ec/google/chromeec/Kconfig
@@ -76,7 +76,8 @@ config EC_GOOGLE_CHROMEEC_SPI_CHIP
 
 config EC_EXTERNAL_FIRMWARE
 	depends on EC_GOOGLE_CHROMEEC
-	def_bool n
+	bool "Disable building EC firmware"
+	default n
 	help
 	  Disable building EC firmware if it's already built externally (and
 	  added manually.)
diff --git a/src/ec/google/chromeec/Makefile.inc b/src/ec/google/chromeec/Makefile.inc
index 7ae1835ffc..9f5f0c1572 100644
--- a/src/ec/google/chromeec/Makefile.inc
+++ b/src/ec/google/chromeec/Makefile.inc
@@ -27,6 +27,7 @@ smm-$(CONFIG_VBOOT_VERIFY_FIRMWARE) += vboot_storage.c
 romstage-$(CONFIG_VBOOT_VERIFY_FIRMWARE) += vboot_storage.c
 verstage-$(CONFIG_VBOOT_VERIFY_FIRMWARE) += vboot_storage.c
 
+ifneq ($(CONFIG_EC_EXTERNAL_FIRMWARE),y)
 # These are Chrome EC firmware images that a payload (such as depthcharge) can
 # use to update the EC. ecrw is the main embedded controller's firmware,
 # pdrw is for a USB PD controller.
@@ -64,5 +65,6 @@ $(obj)/mainboard/$(MAINBOARDDIR)/pdrw:
 	cp $(obj)/external/chromeec/$(CONFIG_EC_GOOGLE_CHROMEEC_PD_BOARDNAME)/RW/ec.RW.flat $@
 
 .PHONY: $(obj)/mainboard/$(MAINBOARDDIR)/ecrw $(obj)/mainboard/$(MAINBOARDDIR)/pdrw
+endif
 
 endif