diff --git a/include/shlguid.h b/include/shlguid.h
index 3af4398209c..e11f9ffb0e8 100644
--- a/include/shlguid.h
+++ b/include/shlguid.h
@@ -99,7 +99,6 @@ DEFINE_GUID(SID_SCommDlgBrowser,  0x80f30233, 0xb7df, 0x11d2, 0xa3, 0x3b, 0x00,
 #define IID_IShellExecuteHook WINELIB_NAME_AW(IID_IShellExecuteHook)
 #define IID_INewShortcutHook  WINELIB_NAME_AW(IID_INewShortcutHook)
 
-DEFINE_GUID(IID_IDockingWindow,     0x012dd920L, 0x7B26, 0x11D0, 0x8C, 0xA9, 0x00, 0xA0, 0xC9, 0x2D, 0xBF, 0xE8);
 DEFINE_GUID(IID_IDockingWindowSite, 0x2A342FC2L, 0x7B26, 0x11D0, 0x8C, 0xA9, 0x00, 0xA0, 0xC9, 0x2D, 0xBF, 0xE8);
 DEFINE_GUID(IID_IInputObject,       0x068284FAA, 0x6A48, 0x11D0, 0x8C, 0x78, 0x00, 0xC0, 0x4F, 0xD9, 0x18, 0xB4);
 DEFINE_GUID(IID_IInputObjectSite,   0x0F1DB8392, 0x7331, 0x11D0, 0x8C, 0x99, 0x00, 0xA0, 0xC9, 0x2D, 0xBF, 0xE8);
diff --git a/include/shobjidl.idl b/include/shobjidl.idl
index 176b63ffd73..c4eac65a9b9 100644
--- a/include/shobjidl.idl
+++ b/include/shobjidl.idl
@@ -1308,6 +1308,27 @@ interface ICommDlgBrowser3 : ICommDlgBrowser2
         [in] IShellView *ppshv);
 }
 
+/*****************************************************************************
+ * IDockingWindow interface
+ */
+[
+    object,
+    uuid(012dd920-7b26-11d0-8ca9-00a0c92dbfe8)
+]
+interface IDockingWindow : IOleWindow
+{
+    HRESULT ShowDW(
+        [in] BOOL fShow);
+
+    HRESULT CloseDW(
+        [in] DWORD dwReserved);
+
+    HRESULT ResizeBorderDW(
+        [in] LPCRECT prcBorder,
+        [in] IUnknown *punkToolbarSite,
+        [in] BOOL fReserved);
+};
+
 
 /*****************************************************************************
  * IDockingWindowFrame interface