diff --git a/include/winbase.h b/include/winbase.h
index a8ccb2c02406b8f3d1973f282c46043d6d685886..4c1d86e12dba4a3cba81235020d822a7bc43b015 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -2511,6 +2511,7 @@ WINBASEAPI BOOL        WINAPI SetCurrentDirectoryW(LPCWSTR);
 WINBASEAPI BOOL        WINAPI SetDefaultCommConfigA(LPCSTR,LPCOMMCONFIG,DWORD);
 WINBASEAPI BOOL        WINAPI SetDefaultCommConfigW(LPCWSTR,LPCOMMCONFIG,DWORD);
 #define                       SetDefaultCommConfig WINELIB_NAME_AW(SetDefaultCommConfig)
+WINBASEAPI BOOL        WINAPI SetDefaultDllDirectories(DWORD);
 WINBASEAPI BOOL        WINAPI SetDllDirectoryA(LPCSTR);
 WINBASEAPI BOOL        WINAPI SetDllDirectoryW(LPCWSTR);
 #define                       SetDllDirectory WINELIB_NAME_AW(SetDllDirectory)