diff --git a/core/Makefile b/core/Makefile
index 179cf29..56b45df 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -317,7 +317,7 @@
 # The string 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 := $(USER)$$($(DATE_FROM_FILE) +%m%d%H%M)
+    BF_BUILD_NUMBER := $(BUILD_USERNAME)$$($(DATE_FROM_FILE) +%m%d%H%M)
   else
     BF_BUILD_NUMBER := $(file <$(BUILD_NUMBER_FILE))
   endif
@@ -420,6 +420,8 @@
 	        BUILD_ID="$(BUILD_ID)" \
 	        BUILD_DISPLAY_ID="$(BUILD_DISPLAY_ID)" \
 	        DATE="$(DATE_FROM_FILE)" \
+	        BUILD_USERNAME="$(BUILD_USERNAME)" \
+	        BUILD_HOSTNAME="$(BUILD_HOSTNAME)" \
 	        BUILD_NUMBER="$(BUILD_NUMBER_FROM_FILE)" \
 	        BOARD_BUILD_SYSTEM_ROOT_IMAGE="$(BOARD_BUILD_SYSTEM_ROOT_IMAGE)" \
 	        AB_OTA_UPDATER="$(AB_OTA_UPDATER)" \
diff --git a/core/main.mk b/core/main.mk
index 9fd1c35..4f81c21 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -80,7 +80,7 @@
 ifeq ($(strip $(HAS_BUILD_NUMBER)),false)
   # BUILD_NUMBER has a timestamp in it, which means that
   # it will change every time.  Pick a stable value.
-  FILE_NAME_TAG := eng.$(USER)
+  FILE_NAME_TAG := eng.$(BUILD_USERNAME)
 else
   FILE_NAME_TAG := $(file <$(BUILD_NUMBER_FILE))
 endif
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 0fd40db..c4f9a52 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -314,7 +314,7 @@
   # If no BUILD_NUMBER is set, create a useful "I am an engineering build
   # from this date/time" value.  Make it start with a non-digit so that
   # anyone trying to parse it as an integer will probably get "0".
-  BUILD_NUMBER := eng.$(shell echo $${USER:0:6}).$(shell $(DATE) +%Y%m%d.%H%M%S)
+  BUILD_NUMBER := eng.$(shell echo $${BUILD_USERNAME:0:6}).$(shell $(DATE) +%Y%m%d.%H%M%S)
   HAS_BUILD_NUMBER := false
 endif
 .KATI_READONLY := BUILD_NUMBER HAS_BUILD_NUMBER