--- a/xpcom/io/SpecialSystemDirectory.cpp
+++ b/xpcom/io/SpecialSystemDirectory.cpp
@@ -111,16 +111,17 @@ GetWindowsFolder(int aFolder, nsIFile** 
   if (len > 1 && path[len - 1] != L'\\') {
     path[len]   = L'\\';
     path[++len] = L'\0';
   }
 
   return NS_NewLocalFile(nsDependentString(path, len), true, aFile);
 }
 
+#if WINVER < 0x0601
 __inline HRESULT
 SHLoadLibraryFromKnownFolder(REFKNOWNFOLDERID aFolderId, DWORD aMode,
                              REFIID riid, void** ppv)
 {
   *ppv = nullptr;
   IShellLibrary* plib;
   HRESULT hr = CoCreateInstance(CLSID_ShellLibrary, nullptr,
                                 CLSCTX_INPROC_SERVER,
@@ -129,16 +130,17 @@ SHLoadLibraryFromKnownFolder(REFKNOWNFOL
     hr = plib->LoadLibraryFromKnownFolder(aFolderId, aMode);
     if (SUCCEEDED(hr)) {
       hr = plib->QueryInterface(riid, ppv);
     }
     plib->Release();
   }
   return hr;
 }
+#endif
 
 /*
  * Check to see if we're on Win7 and up, and if so, returns the default
  * save-to location for the Windows Library passed in through aFolderId.
  * Otherwise falls back on pre-win7 GetWindowsFolder.
  */
 static nsresult
 GetLibrarySaveToPath(int aFallbackFolderId, REFKNOWNFOLDERID aFolderId,