diff --git a/Makefile b/Makefile
index 14768cd2f..fa2acb282 100644
--- a/Makefile
+++ b/Makefile
@@ -168,3 +168,6 @@ $(ELF): $(OBJ_DIR)/ld_script.ld $(OBJS)
 
 $(ROM): $(ELF)
 	$(OBJCOPY) -O binary --gap-fill 0xFF --pad-to 0x9000000 $< $@
+
+baserom.gba: ;
+	$(error baserom.gba is required to build)