diff --git a/dlls/user32/nonclient.c b/dlls/user32/nonclient.c
index 03831a3ba8f..ccea5178f6f 100644
--- a/dlls/user32/nonclient.c
+++ b/dlls/user32/nonclient.c
@@ -533,17 +533,17 @@ static LRESULT NC_DoNCHitTest (WND *wndPtr, POINT pt )
     RECT rect, rcClient;
     POINT ptClient;
 
-    TRACE("hwnd=%p pt=%d,%d\n", wndPtr->hwndSelf, pt.x, pt.y );
+    TRACE("hwnd=%p pt=%d,%d\n", wndPtr->obj.handle, pt.x, pt.y );
 
-    GetWindowRect(wndPtr->hwndSelf, &rect );
+    GetWindowRect(wndPtr->obj.handle, &rect );
     if (!PtInRect( &rect, pt )) return HTNOWHERE;
 
     if (wndPtr->dwStyle & WS_MINIMIZE) return HTCAPTION;
 
     /* Check client area */
     ptClient = pt;
-    ScreenToClient( wndPtr->hwndSelf, &ptClient );
-    GetClientRect( wndPtr->hwndSelf, &rcClient );
+    ScreenToClient( wndPtr->obj.handle, &ptClient );
+    GetClientRect( wndPtr->obj.handle, &rcClient );
     if (PtInRect( &rcClient, ptClient )) return HTCLIENT;
 
     /* Check borders */
@@ -606,7 +606,7 @@ static LRESULT NC_DoNCHitTest (WND *wndPtr, POINT pt )
             /* Check system menu */
             if ((wndPtr->dwStyle & WS_SYSMENU) && !(wndPtr->dwExStyle & WS_EX_TOOLWINDOW))
             {
-                if (NC_IconForWindow(wndPtr->hwndSelf))
+                if (NC_IconForWindow(wndPtr->obj.handle))
                     rect.left += GetSystemMetrics(SM_CYCAPTION) - 1;
             }
             if (pt.x < rect.left) return HTSYSMENU;
diff --git a/dlls/user32/win.c b/dlls/user32/win.c
index 28ea84119b5..be40018e464 100644
--- a/dlls/user32/win.c
+++ b/dlls/user32/win.c
@@ -250,12 +250,12 @@ static WND *create_window_handle( HWND parent, HWND owner, LPCWSTR name,
     index = USER_HANDLE_TO_INDEX(handle);
     assert( index < NB_USER_HANDLES );
     user_handles[index] = win;
-    win->hwndSelf   = handle;
+    win->obj.handle = handle;
+    win->obj.type   = USER_WINDOW;
     win->parent     = full_parent;
     win->owner      = full_owner;
     win->class      = class;
     win->winproc    = get_class_winproc( class );
-    win->dwMagic    = WND_MAGIC;
     win->cbWndExtra = extra_bytes;
     if (WINPROC_IsUnicode( win->winproc, unicode )) win->flags |= WIN_ISUNICODE;
     return win;
@@ -267,31 +267,23 @@ static WND *create_window_handle( HWND parent, HWND owner, LPCWSTR name,
  *
  * Free a window handle.
  */
-static WND *free_window_handle( HWND hwnd )
+static void free_window_handle( HWND hwnd )
 {
-    WND *ptr;
+    struct user_object *ptr;
     WORD index = USER_HANDLE_TO_INDEX(hwnd);
 
-    if (index >= NB_USER_HANDLES) return NULL;
-    USER_Lock();
-    if ((ptr = user_handles[index]))
+    if ((ptr = get_user_handle_ptr( hwnd, USER_WINDOW )) && ptr != OBJ_OTHER_PROCESS)
     {
         SERVER_START_REQ( destroy_window )
         {
             req->handle = wine_server_user_handle( hwnd );
-            if (!wine_server_call_err( req ))
-            {
-                user_handles[index] = NULL;
-                ptr->dwMagic = 0;
-            }
-            else
-                ptr = NULL;
+            if (!wine_server_call_err( req )) user_handles[index] = NULL;
+            else ptr = NULL;
         }
         SERVER_END_REQ;
+        release_user_handle_ptr( ptr );
+        HeapFree( GetProcessHeap(), 0, ptr );
     }
-    USER_Unlock();
-    HeapFree( GetProcessHeap(), 0, ptr );
-    return ptr;
 }
 
 
@@ -494,22 +486,12 @@ BOOL is_desktop_window( HWND hwnd )
  */
 WND *WIN_GetPtr( HWND hwnd )
 {
-    WND * ptr;
-    WORD index = USER_HANDLE_TO_INDEX(hwnd);
+    WND *ptr;
 
-    if (index >= NB_USER_HANDLES) return NULL;
-
-    USER_Lock();
-    if ((ptr = user_handles[index]))
+    if ((ptr = get_user_handle_ptr( hwnd, USER_WINDOW )) == WND_OTHER_PROCESS)
     {
-        if (ptr->dwMagic == WND_MAGIC &&
-            (hwnd == ptr->hwndSelf || !HIWORD(hwnd) || HIWORD(hwnd) == 0xffff))
-            return ptr;
-        ptr = NULL;
+        if (is_desktop_window( hwnd )) ptr = WND_DESKTOP;
     }
-    else if (is_desktop_window( hwnd )) ptr = WND_DESKTOP;
-    else ptr = WND_OTHER_PROCESS;
-    USER_Unlock();
     return ptr;
 }
 
@@ -525,7 +507,7 @@ HWND WIN_IsCurrentProcess( HWND hwnd )
     HWND ret;
 
     if (!(ptr = WIN_GetPtr( hwnd )) || ptr == WND_OTHER_PROCESS || ptr == WND_DESKTOP) return 0;
-    ret = ptr->hwndSelf;
+    ret = ptr->obj.handle;
     WIN_ReleasePtr( ptr );
     return ret;
 }
@@ -542,7 +524,7 @@ HWND WIN_IsCurrentThread( HWND hwnd )
     HWND ret = 0;
 
     if (!(ptr = WIN_GetPtr( hwnd )) || ptr == WND_OTHER_PROCESS || ptr == WND_DESKTOP) return 0;
-    if (ptr->tid == GetCurrentThreadId()) ret = ptr->hwndSelf;
+    if (ptr->tid == GetCurrentThreadId()) ret = ptr->obj.handle;
     WIN_ReleasePtr( ptr );
     return ret;
 }
@@ -572,7 +554,7 @@ HWND WIN_Handle32( HWND16 hwnd16 )
 
     if (ptr != WND_OTHER_PROCESS)
     {
-        hwnd = ptr->hwndSelf;
+        hwnd = ptr->obj.handle;
         WIN_ReleasePtr( ptr );
     }
     else  /* may belong to another process */
@@ -832,7 +814,6 @@ static void destroy_thread_window( HWND hwnd )
         sys_menu = wndPtr->hSysMenu;
         free_dce( wndPtr->dce, hwnd );
         user_handles[index] = NULL;
-        wndPtr->dwMagic = 0;
     }
     USER_Unlock();
 
@@ -1219,7 +1200,7 @@ static HWND WIN_CreateWindowEx( CREATESTRUCTA *cs, LPCWSTR className, UINT flags
 
     if (!(wndPtr = create_window_handle( parent, owner, className, cs->hInstance, unicode )))
         return 0;
-    hwnd = wndPtr->hwndSelf;
+    hwnd = wndPtr->obj.handle;
 
     /* Fill the window structure */
 
@@ -3305,7 +3286,7 @@ BOOL WINAPI FlashWindow( HWND hWnd, BOOL bInvert )
 
         wndPtr = WIN_GetPtr(hWnd);
         if (!wndPtr || wndPtr == WND_OTHER_PROCESS || wndPtr == WND_DESKTOP) return FALSE;
-        hWnd = wndPtr->hwndSelf;  /* make it a full handle */
+        hWnd = wndPtr->obj.handle;  /* make it a full handle */
 
         if (bInvert) wparam = !(wndPtr->flags & WIN_NCACTIVATED);
         else wparam = (hWnd == GetForegroundWindow());
diff --git a/dlls/user32/win.h b/dlls/user32/win.h
index 5cd879ab5fb..743c67e1fa6 100644
--- a/dlls/user32/win.h
+++ b/dlls/user32/win.h
@@ -28,20 +28,19 @@
 #include <winuser.h>
 #include <wine/windef16.h>
 
-#define WND_MAGIC     0x444e4957  /* 'WIND' */
+#include "user_private.h"
 
 struct tagCLASS;
 struct tagDIALOGINFO;
 
 typedef struct tagWND
 {
-    HWND           hwndSelf;      /* Handle of this window */
+    struct user_object obj;       /* object header */
     HWND           parent;        /* Window parent */
     HWND           owner;         /* Window owner */
     struct tagCLASS *class;       /* Window class */
     struct dce    *dce;           /* DCE pointer */
     WNDPROC        winproc;       /* Window procedure */
-    DWORD          dwMagic;       /* Magic number (must be WND_MAGIC) */
     DWORD          tid;           /* Owner thread id */
     HINSTANCE      hInstance;     /* Window hInstance (from CreateWindow) */
     RECT           rectClient;    /* Client area rel. to parent client area */
diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
index 72532dee8f9..c62fdaa7460 100644
--- a/dlls/user32/winpos.c
+++ b/dlls/user32/winpos.c
@@ -1790,7 +1790,7 @@ static BOOL fixup_flags( WINDOWPOS *winpos )
         SetLastError( ERROR_INVALID_WINDOW_HANDLE );
         return FALSE;
     }
-    winpos->hwnd = wndPtr->hwndSelf;  /* make it a full handle */
+    winpos->hwnd = wndPtr->obj.handle;  /* make it a full handle */
 
     /* Finally make sure that all coordinates are valid */
     if (winpos->x < -32768) winpos->x = -32768;