diff --git a/target/imagebuilder/files/Makefile b/target/imagebuilder/files/Makefile
index 8b386a33c6..0d997d6200 100644
--- a/target/imagebuilder/files/Makefile
+++ b/target/imagebuilder/files/Makefile
@@ -20,6 +20,7 @@ ifeq ($(KBUILD_VERBOSE),99)
   MAKE:=3>/dev/null $(MAKE)
 endif
 export IS_TTY=$(shell tty -s && echo 1 || echo 0)
+export IMAGEBUILDER=1
 
 # override variables from rules.mk
 PACKAGE_DIR:=$(TOPDIR)/packages