diff --git a/core/sysprop.mk b/core/sysprop.mk
index 4536e5f..a37fd05 100644
--- a/core/sysprop.mk
+++ b/core/sysprop.mk
@@ -186,15 +186,8 @@
 # BUILD_FINGERPRINT is used used to uniquely identify the combined build and
 # product; used by the OTA server.
 ifeq (,$(strip $(BUILD_FINGERPRINT)))
-  ifeq ($(strip $(HAS_BUILD_NUMBER)),false)
-    BF_BUILD_NUMBER := $(BUILD_USERNAME)$$($(DATE_FROM_FILE) +%m%d%H%M)
-  else
-    BF_BUILD_NUMBER := $(BUILD_NUMBER_FROM_FILE)
-  endif
-  BUILD_FINGERPRINT := $(PRODUCT_BRAND)/$(TARGET_PRODUCT)/$(TARGET_DEVICE):$(PLATFORM_VERSION)/$(BUILD_ID)/$(BF_BUILD_NUMBER):$(TARGET_BUILD_VARIANT)/$(BUILD_VERSION_TAGS)
+  BUILD_FINGERPRINT := $(PRODUCT_BRAND)/$(TARGET_PRODUCT)/$(TARGET_DEVICE):$(PLATFORM_VERSION)/$(BUILD_ID)/$(BUILD_NUMBER_FROM_FILE):$(TARGET_BUILD_VARIANT)/$(BUILD_VERSION_TAGS)
 endif
-# unset it for safety.
-BF_BUILD_NUMBER :=
 
 BUILD_FINGERPRINT_FILE := $(PRODUCT_OUT)/build_fingerprint.txt
 ifneq (,$(shell mkdir -p $(PRODUCT_OUT) && echo $(BUILD_FINGERPRINT) >$(BUILD_FINGERPRINT_FILE) && grep " " $(BUILD_FINGERPRINT_FILE)))