diff --git a/reactos/CMakeLists.txt b/reactos/CMakeLists.txt
index b65cdc759d9..07af3c2b416 100644
--- a/reactos/CMakeLists.txt
+++ b/reactos/CMakeLists.txt
@@ -37,7 +37,7 @@ elseif(ARCH MATCHES arm)
     include(config-arm.cmake)
 endif()
 
-add_definitions(-D__REACTOS__ __ROS_CMAKE__)
+add_definitions(-D__REACTOS__ -D__ROS_CMAKE__)
 
 if(NOT CMAKE_CROSSCOMPILING)