diff --git a/CMakeLists.txt b/CMakeLists.txt
index c8fa4f7ff..e84ff400f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -368,9 +368,17 @@ IF (CMAKE_COMPILER_IS_GNUCXX AND ((CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL "4.8
    SET(WERROR_FLAGS "${WERROR_FLAGS} -Wno-array-bounds")
 ENDIF()
 
-SET(CMAKE_C_FLAGS "-O2 -g ${WERROR_FLAGS} ${CMAKE_C_FLAGS}")
-SET(CMAKE_CXX_FLAGS "-O2 -g -fno-exceptions ${WERROR_FLAGS} ${CMAKE_CXX_FLAGS}")
-SET(CMAKE_C_FLAGS_DEBUG "-DLMMS_DEBUG")
+IF(NOT CMAKE_BUILD_TYPE)
+	message(STATUS "Setting build type to 'Release' as none was specified.")
+	set(CMAKE_BUILD_TYPE Release CACHE STRING "Choose the type of build." FORCE)
+	# Set the possible values of build type for cmake-gui
+	SET_PROPERTY(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
+  		"MinSizeRel" "RelWithDebInfo")
+ENDIF()
+
+SET(CMAKE_C_FLAGS "${WERROR_FLAGS} ${CMAKE_C_FLAGS}")
+SET(CMAKE_CXX_FLAGS "-fno-exceptions ${WERROR_FLAGS} ${CMAKE_CXX_FLAGS}")
+SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -DLMMS_DEBUG")
 
 
 # people simply updating git will still have this and mess up build with it