diff --git a/include/shdeprecated.idl b/include/shdeprecated.idl
index ec05f4ff4b6..1f001fd6f0d 100644
--- a/include/shdeprecated.idl
+++ b/include/shdeprecated.idl
@@ -400,8 +400,8 @@ interface IBrowserService2 : IBrowserService
     LRESULT WndProcBS(
         [in] HWND hwnd,
         [in] UINT uMsg,
-        [in, out] WPARAM wParam,
-        [in, out] LPARAM lParam);
+        [in] WPARAM wParam,
+        [in] LPARAM lParam);
 
     HRESULT SetAsDefFolderSettings();
 
@@ -511,8 +511,8 @@ interface IBrowserService2 : IBrowserService
         [in] HWND hwndBar,
         [in] BOOL fBroadcast,
         [in] UINT uMsg,
-        [in, out] WPARAM wParam,
-        [in, out] LPARAM lParam);
+        [in] WPARAM wParam,
+        [in] LPARAM lParam);
 
     HRESULT GetFolderSetData(
         [in, out] struct tagFolderSetData *pfsd);