diff --git a/reactos/cmake/gcc.cmake b/reactos/cmake/gcc.cmake
index 0ab9a7cb649..796ebafbe1a 100644
--- a/reactos/cmake/gcc.cmake
+++ b/reactos/cmake/gcc.cmake
@@ -32,8 +32,7 @@ if(GCC_VERSION VERSION_GREATER 4.7)
 endif()
 
 if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
-    add_compile_flags_language("-std=gnu89" "C")
-    add_compile_flags("-Wno-microsoft")
+    add_compile_flags_language("-std=gnu89 -Wno-microsoft" "C")
     set(CMAKE_LINK_DEF_FILE_FLAG "")
     set(CMAKE_STATIC_LIBRARY_SUFFIX ".a")
     set(CMAKE_LINK_LIBRARY_SUFFIX "")