diff --git a/vpython b/vpython
index e57873cdb..63dbf5441 100755
--- a/vpython
+++ b/vpython
@@ -39,4 +39,17 @@ base_dir=$(dirname "$0")
 source "$base_dir/cipd_bin_setup.sh"
 cipd_bin_setup &> /dev/null
 
-exec "$base_dir/.cipd_bin/vpython" "$@"
+# If Python bootstrapping is not disabled, make sure Python has been
+# bootstrapped and add it to the front of PATH.
+if [[ $(uname -s) = MINGW* || $(uname -s) = CYGWIN* ]]; then
+  cmd.exe //c $0.bat "$@"
+elif [[ $DEPOT_TOOLS_BOOTSTRAP_PYTHON3 != 0 ]]; then
+  if [[ ! -e "$base_dir/python_bin_reldir.txt" ]]; then
+    source "$base_dir/bootstrap_python3"
+    bootstrap_python3
+  fi
+  PYTHON_BIN_RELDIR="$base_dir/$(cat "$base_dir/python_bin_reldir.txt" | xargs echo)"
+  exec "$base_dir/.cipd_bin/vpython" -vpython-interpreter  "$PYTHON_BIN_RELDIR/python" "$@"
+else
+  exec "$base_dir/.cipd_bin/vpython" "$@"
+fi