diff --git a/include/ole2.h b/include/ole2.h
index fdf821c1a81218e382b2b6edf198c63f792c050b..5a0efdd5095760d751ff67b1a57cff1c6110592e 100644
--- a/include/ole2.h
+++ b/include/ole2.h
@@ -80,7 +80,7 @@ HRESULT     WINAPI OleCreateLink(LPMONIKER pmkLinkSrc, REFIID riid, DWORD render
                 LPOLECLIENTSITE pClientSite, LPSTORAGE pStg, LPVOID* ppvObj);
 HRESULT     WINAPI OleCreate(REFCLSID rclsid, REFIID riid, DWORD renderopt, LPFORMATETC pFormatEtc, LPOLECLIENTSITE pClientSite,
                 LPSTORAGE pStg, LPVOID* ppvObj);
-HRESULT     WINAPI OleFlushClipboard();
+HRESULT     WINAPI OleFlushClipboard(void);
 HRESULT     WINAPI SetConvertStg(LPSTORAGE pStg, BOOL fConvert);
 BOOL        WINAPI IsAccelerator(HACCEL hAccel, int cAccelEntries, LPMSG lpMsg, WORD* lpwCmd);
 HRESULT     WINAPI OleCreateLinkToFile(LPCOLESTR lpszFileName, REFIID riid, DWORD renderopt, LPFORMATETC lpFormatEtc,