diff --git a/modules/rostests/apitests/user32/RealGetWindowClass.c b/modules/rostests/apitests/user32/RealGetWindowClass.c
index 856c28c71f8..e5274d5cc31 100644
--- a/modules/rostests/apitests/user32/RealGetWindowClass.c
+++ b/modules/rostests/apitests/user32/RealGetWindowClass.c
@@ -7,8 +7,6 @@
 
 #include "precomp.h"
 
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
-
 static PWSTR ControlsList[] =
 {
   L"Button\0",
diff --git a/sdk/include/reactos/wine/test.h b/sdk/include/reactos/wine/test.h
index 25c4ff56819..0b4c54019c1 100644
--- a/sdk/include/reactos/wine/test.h
+++ b/sdk/include/reactos/wine/test.h
@@ -155,6 +155,7 @@ extern void __winetest_cdecl winetest_trace( const char *msg, ... );
 #define todo_wine_if(is_todo)   todo_if((is_todo) && !strcmp(winetest_platform, "wine"))
 #endif
 
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 #ifdef NONAMELESSUNION
 # define U(x)  (x).u