diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3b5f75214b6fc63c452fde50f1489dbea0844722..d79d1c8756f4e155f7b5d515c4e93bfa85ae364a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -117,15 +117,12 @@ message(STATUS "Set CMAKE_SYSTEM_LIBRARY_PATH to ${CMAKE_SYSTEM_LIBRARY_PATH}")
 ##################################################################################
 set(CSTANDARD "")
 set(CDEBUG    "")
-set(CWARN     "-Wall -Wextra -Wno-main -Wstrict-overflow=5 -Winline")
-set(CTUNING   "-fstrict-overflow -fno-strict-aliasing")
-set(COPT      "-Os")
-set(CMCU      "-mmcu=${MCU}")
-#set(CDEFS     "-DF_CPU=${F_CPU}") Have to set this using the line below otherwise we get errors about not defining F_CPU
-add_definitions(-DF_CPU=${F_CPU})
-
-set(CMAKE_C_CFLAGS "${CMCU} ${CDEBUG} ${CDEFS} ${COPT} ${CWARN} ${CSTANDARD} ${CTUNING}")
+set(CWARN     -Wall -Wextra -Wno-main -Wstrict-overflow=5 -Winline)
+set(CTUNING   -fstrict-overflow -fno-strict-aliasing)
+set(COPT      -Os)
 
+add_definitions(-DF_CPU=${F_CPU})
+add_compile_options(${CDEBUG} ${COPT} ${CWARN} ${CSTANDARD} ${CTUNING})
 
 
 ### File Discovery