diff --git a/reactos/cmake/Platform/Windows-cl.cmake b/reactos/cmake/Platform/Windows-cl.cmake
index 7ed6229adec..76c1f6fb983 100644
--- a/reactos/cmake/Platform/Windows-cl.cmake
+++ b/reactos/cmake/Platform/Windows-cl.cmake
@@ -208,8 +208,8 @@ endif()
 #SET(CMAKE_C_LINK_EXECUTABLE "<CMAKE_COMMAND> -E vs_link_exe ${CMAKE_C_LINK_EXECUTABLE}")
 
 SET(CMAKE_BUILD_TYPE_INIT Debug)
-SET(CMAKE_CXX_FLAGS_DEBUG_INIT "/D_DEBUG /Zi /Ob0 /Od")
-SET(CMAKE_C_FLAGS_DEBUG_INIT "/D_DEBUG /Zi /Ob0 /Od")
+SET(CMAKE_CXX_FLAGS_DEBUG_INIT "/Zi /Ob0 /Od")
+SET(CMAKE_C_FLAGS_DEBUG_INIT "/Zi /Ob0 /Od")
 SET(CMAKE_CXX_FLAGS_INIT "")
 SET(CMAKE_CXX_FLAGS_MINSIZEREL_INIT "/O1 /Ob1 /D NDEBUG")
 SET(CMAKE_CXX_FLAGS_RELEASE_INIT "/O2 /Ob2 /D NDEBUG")