--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -51,7 +51,7 @@
     message(STATUS "Debug build")
     add_definitions(-DDEBUG)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -O0")
-else()
+elseif(CMAKE_BUILD_TYPE MATCHES Release)
     message(STATUS "Release build")
     add_definitions(-DNDEBUG)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")