diff --git a/WeaselSetup/WeaselSetup.cpp b/WeaselSetup/WeaselSetup.cpp
index e9a1e56e7..43286ecfb 100644
--- a/WeaselSetup/WeaselSetup.cpp
+++ b/WeaselSetup/WeaselSetup.cpp
@@ -136,6 +136,12 @@ static int CustomInstall(bool installing) {
   return 0;
 }
 
+LPCTSTR GetParamByPrefix(LPCTSTR lpCmdLine, LPCTSTR prefix) {
+  return (wcsncmp(lpCmdLine, prefix, wcslen(prefix)) == 0)
+             ? (lpCmdLine + wcslen(prefix))
+             : 0;
+}
+
 static int Run(LPTSTR lpCmdLine) {
   constexpr bool silent = true;
   constexpr bool old_ime_support = false;
@@ -147,6 +153,11 @@ static int Run(LPTSTR lpCmdLine) {
       return RestartAsAdmin(lpCmdLine);
   }
 
+  if (auto res = GetParamByPrefix(lpCmdLine, L"/userdir:")) {
+    return SetRegKeyValue(HKEY_CURRENT_USER, L"Software\\Rime\\weasel",
+                          L"RimeUserDir", res, REG_SZ);
+  }
+
   if (!wcscmp(L"/ls", lpCmdLine)) {
     return SetRegKeyValue(HKEY_CURRENT_USER, L"Software\\Rime\\weasel",
                           L"Language", L"chs", REG_SZ);