diff --git a/win_toolchain/package_from_installed.py b/win_toolchain/package_from_installed.py
index c515c63bc..e1bea2afc 100644
--- a/win_toolchain/package_from_installed.py
+++ b/win_toolchain/package_from_installed.py
@@ -216,7 +216,8 @@ def GenerateSetEnvCmd(target_dir):
       f.write('%~dp0..\\..\\win_sdk\\Include\\WINVERSION\\ucrt;'.replace(
                   'WINVERSION', WIN_VERSION))
     f.write('%~dp0..\\..\\VC\\include;'
-            '%~dp0..\\..\\VC\\atlmfc\\include\n')
+            '%~dp0..\\..\\VC\\atlmfc\\include\n'
+            'if "%1"=="/x64" goto x64\n')
 
     # x86. Always use amd64_x86 cross, not x86 on x86.
     f.write('set PATH=%~dp0..\\..\\win_sdk\\bin\\x86;'