diff --git a/CMakeLists.txt b/CMakeLists.txt
index d362de68..306507e1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -118,6 +118,7 @@ else()
 endif()
 
 if (WITH_UART)
+	add_definitions(-DWITH_UART)
 	set(SOURCES ${SOURCES} "uart.cpp")
 endif()