diff --git a/core/Makefile b/core/Makefile
index 2841253624..8168203019 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -5379,7 +5379,7 @@ ifdef BOARD_PREBUILT_INIT_BOOT_IMAGE
 	$(hide) cp $(INSTALLED_INIT_BOOT_IMAGE_TARGET) $(zip_root)/PREBUILT_IMAGES/
 endif
 ifndef BOARD_PREBUILT_BOOTIMAGE
-ifneq (,$(INTERNAL_PREBUILT_BOOTIMAGE) $(filter true,$(BOARD_COPY_BOOT_IMAGE_TO_TARGET_FILES)))
+ifneq (,$(strip $(INTERNAL_PREBUILT_BOOTIMAGE) $(filter true,$(BOARD_COPY_BOOT_IMAGE_TO_TARGET_FILES))))
 ifdef INSTALLED_BOOTIMAGE_TARGET
 	$(hide) mkdir -p $(zip_root)/IMAGES
 	$(hide) cp $(INSTALLED_BOOTIMAGE_TARGET) $(zip_root)/IMAGES/