diff --git a/Android.mk b/Android.mk
index b667fd2..26ec098 100644
--- a/Android.mk
+++ b/Android.mk
@@ -52,8 +52,18 @@
 PLAT_PRIVATE_POLICY := $(LOCAL_PATH)/private
 PLAT_VENDOR_POLICY := $(LOCAL_PATH)/vendor
 REQD_MASK_POLICY := $(LOCAL_PATH)/reqd_mask
-SYSTEM_EXT_PUBLIC_POLICY := $(BOARD_PLAT_PUBLIC_SEPOLICY_DIR)
-SYSTEM_EXT_PRIVATE_POLICY := $(BOARD_PLAT_PRIVATE_SEPOLICY_DIR)
+
+SYSTEM_EXT_PUBLIC_POLICY := $(SYSTEM_EXT_PUBLIC_SEPOLICY_DIRS)
+ifneq (,$(BOARD_PLAT_PUBLIC_SEPOLICY_DIR))
+  # TODO: Disallow BOARD_PLAT_*
+  SYSTEM_EXT_PUBLIC_POLICY += $(BOARD_PLAT_PUBLIC_SEPOLICY_DIR)
+endif
+SYSTEM_EXT_PRIVATE_POLICY := $(SYSTEM_EXT_PRIVATE_SEPOLICY_DIRS)
+ifneq (,$(BOARD_PLAT_PRIVATE_SEPOLICY_DIR))
+  # TODO: Disallow BOARD_PLAT_*
+  SYSTEM_EXT_PRIVATE_POLICY += $(BOARD_PLAT_PRIVATE_SEPOLICY_DIR)
+endif
+
 PRODUCT_PUBLIC_POLICY := $(PRODUCT_PUBLIC_SEPOLICY_DIRS)
 PRODUCT_PRIVATE_POLICY := $(PRODUCT_PRIVATE_SEPOLICY_DIRS)