diff --git a/CMakeLists.txt b/CMakeLists.txt
index e34a342ab..306b897d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -108,7 +108,7 @@ if (CMAKE_BUILD_TYPE MATCHES Debug)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wno-attributes -O0") #support C++11 for std::, optimize
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -O0")
 else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wno-attributes -O2") #support C++11 for std::, optimize
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wno-attributes -O2 -DNDEBUG") #support C++11 for std::, optimize
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -O2")  #-s = strip binary
 endif()
 endif()