diff --git a/examples/uartdemo/Makefile b/examples/uartdemo/Makefile
index 0d5fb5db5e9774041496f06fc54a5a8660cb1887..e13216a7c03d49032e108a274fb54d8795c627d4 100644
--- a/examples/uartdemo/Makefile
+++ b/examples/uartdemo/Makefile
@@ -2,8 +2,6 @@ all : flash
 
 TARGET:=uartdemo
 
-CFLAGS+=-DSTDOUT_UART
-
 include ../../ch32v003fun/ch32v003fun.mk
 
 flash : cv_flash