diff --git a/update_depot_tools.bat b/update_depot_tools.bat
index 84b0a1f..983a29e 100644
--- a/update_depot_tools.bat
+++ b/update_depot_tools.bat
@@ -29,7 +29,7 @@
 
 :: Initialize/update virtualenv.
 cd /d "%DEPOT_TOOLS_DIR%."
-python -u bootstrap\bootstrap.py --deps_file bootstrap\deps.pyl --quiet ENV
+call python.bat -u bootstrap\bootstrap.py --deps_file bootstrap\deps.pyl --quiet ENV
 if errorlevel 1 goto :EOF
 
 :: Shall skip automatic update?