diff --git a/Makefile b/Makefile
index 5573127..52f6c98 100644
--- a/Makefile
+++ b/Makefile
@@ -921,7 +921,7 @@
 endif
 
 ifneq ($(NEED_SERIAL), )
-LIB_OBJS += serial.o
+LIB_OBJS += serial.o custom_baud.o
 endif
 
 ifneq ($(NEED_POSIX_SOCKETS), )