diff --git a/core/config.mk b/core/config.mk
index 844d7d6..ba77990 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -820,7 +820,7 @@
   MAINLINE_SEPOLICY_DEV_CERTIFICATES := $(dir $(DEFAULT_SYSTEM_DEV_CERTIFICATE))
 endif
 
-BUILD_NUMBER_FROM_FILE := $$(cat $(OUT_DIR)/build_number.txt)
+BUILD_NUMBER_FROM_FILE := $$(cat $(SOONG_OUT_DIR)/build_number.txt)
 BUILD_DATETIME_FROM_FILE := $$(cat $(BUILD_DATETIME_FILE))
 
 # SEPolicy versions