diff --git a/CMakeLists.txt b/CMakeLists.txt
index 56453252a2..d7c5f38adb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -73,7 +73,7 @@ else(DEBUG_MODE)
   set(CMAKE_BUILD_TYPE RELEASE)
 endif(DEBUG_MODE)
 
-set(CMAKE_C_FLAGS_DEBUG "-DCOCOS2D_DEBUG=1")
+set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -DCOCOS2D_DEBUG=1")
 set(CMAKE_CXX_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})
 
 # Compiler options