diff --git a/export-chrome-bookmarks.sh b/export-chrome-bookmarks.sh
index 51df5df..fbae51e 100755
--- a/export-chrome-bookmarks.sh
+++ b/export-chrome-bookmarks.sh
@@ -1,3 +1,16 @@
-#!/bin/bash
+#!/usr/bin/env nix-shell
+#!nix-shell --pure -i bash -p dejsonlz4 jq bash -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/fea633695211167753ee732c9087808d0c57461c.tar.gz
 
-jq '.roots[] | recurse(.children?[]?) | "\( .name? ): \( .url? )"' ~suzanne/apps/chromium/.config/chromium/Default/Bookmarks
+# Usage: ./export-firefox-bookmarks.sh [path/to/.mozilla/firefox/XXXXXXXX.profile]
+
+set -euET -o pipefail
+
+if test $# -ge 1; then
+  profile="$1"
+else
+  # use printf to avoid echo's ambiguity; save trailing whitespace with a dummy x (not needed here as the string ends with "Default", but a good habit nevertheless)
+  profile="$(printf "%sx" ~/.config/chromium/Default/)"
+  profile="${profile%x}"
+fi
+
+jq '.roots[] | recurse(.children?[]?) | "\( .name? ): \( .url? )"' < "$profile"/Bookmarks