diff --git a/CMakeLists.txt b/CMakeLists.txt
index f80f5fc..2184288 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,6 +21,10 @@ include_directories(Peripheral/inc)
 
 add_definitions(-Wall -Wextra -march=rv32ec_zicsr -mabi=ilp32e -msmall-data-limit=0 -msave-restore -Os -fmessage-length=0 -fsigned-char -ffunction-sections -fdata-sections -fno-common)
 
+IF(SDI_PRINTF)
+    add_definitions(-DSDI_PRINT=1)
+ENDIF(SDI_PRINTF)
+
 file(GLOB SOURCES "Debug/*.c" "Core/*.c" "User/*.c" "Peripheral/src/*.c" "Startup/*.S")
 
 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_PROJECT_NAME}.hex