diff --git a/reactos/dll/win32/user32/user32.def b/reactos/dll/win32/user32/user32.def
index ab4a7004921..c4a547e54ed 100644
--- a/reactos/dll/win32/user32/user32.def
+++ b/reactos/dll/win32/user32/user32.def
@@ -704,7 +704,7 @@ UnregisterDeviceNotification@4
 UnregisterHotKey@8=NtUserUnregisterHotKey@8
 UnregisterMessagePumpHook@0
 UnregisterUserApiHook@0
-UpdateLayeredWindow@36
+UpdateLayeredWindow@36=NtUserUpdateLayeredWindow@36
 UpdatePerUserSystemParameters@8
 UpdateWindow@4
 User32InitializeImmEntryTable@4
diff --git a/reactos/dll/win32/user32/windows/window.c b/reactos/dll/win32/user32/windows/window.c
index bf2d0b337d9..908d9b261cc 100644
--- a/reactos/dll/win32/user32/windows/window.c
+++ b/reactos/dll/win32/user32/windows/window.c
@@ -1762,15 +1762,8 @@ TileWindows(HWND hwndParent,
  * @unimplemented
  */
 BOOL STDCALL
-UpdateLayeredWindow(HWND hwnd,
-                    HDC hdcDst,
-                    POINT *pptDst,
-                    SIZE *psize,
-                    HDC hdcSrc,
-                    POINT *pptSrc,
-                    COLORREF crKey,
-                    BLENDFUNCTION *pblend,
-                    DWORD dwFlags)
+UpdateLayeredWindowIndirect(HWND hwnd,
+                            const UPDATELAYEREDWINDOWINFO *info)
 {
     UNIMPLEMENTED;
     return FALSE;
diff --git a/reactos/include/psdk/winuser.h b/reactos/include/psdk/winuser.h
index c2a04e7e4b2..d5cfbdc4e67 100644
--- a/reactos/include/psdk/winuser.h
+++ b/reactos/include/psdk/winuser.h
@@ -2594,6 +2594,10 @@ extern "C" {
 #define LWA_COLORKEY 1
 #define LWA_ALPHA 2
 #endif
+#define ULW_COLORKEY        0x00000001
+#define ULW_ALPHA           0x00000002
+#define ULW_OPAQUE          0x00000004
+#define ULW_EX_NORESIZE     0x00000008
 #define GA_PARENT 1
 #define GA_ROOT 2
 #define GA_ROOTOWNER 3
@@ -4279,6 +4283,20 @@ BOOL WINAPI LockSetForegroundWindow(UINT);
 BOOL WINAPI SetLayeredWindowAttributes(HWND,COLORREF,BYTE,DWORD);
 #if defined(_WINGDI_) && !defined(NOGDI)
 BOOL WINAPI UpdateLayeredWindow(HWND,HDC,POINT*,SIZE*,HDC,POINT*,COLORREF,BLENDFUNCTION*,DWORD);
+typedef struct tagUPDATELAYEREDWINDOWINFO
+{
+    DWORD                cbSize;
+    HDC                  hdcDst;
+    POINT CONST*         pptDst;
+    SIZE CONST*          psize;
+    HDC                  hdcSrc;
+    POINT CONST*         pptSrc;
+    COLORREF             crKey;
+    BLENDFUNCTION CONST* pblend;
+    DWORD                dwFlags;
+    RECT CONST*          prcDirty;
+} UPDATELAYEREDWINDOWINFO, *PUPDATELAYEREDWINDOWINFO;
+BOOL WINAPI UpdateLayeredWindowIndirect(HWND,UPDATELAYEREDWINDOWINFO CONST*);
 #endif
 #endif
 #if (_WIN32_WINNT >= 0x0501)