diff --git a/datasette/templates/query.html b/datasette/templates/query.html
index 9416e225..46aac76f 100644
--- a/datasette/templates/query.html
+++ b/datasette/templates/query.html
@@ -25,7 +25,7 @@
 
 {% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
 
-<form class="sql" action="/{{ database_url(database) }}{% if canned_query %}/{{ canned_query }}{% endif %}" method="get">
+<form class="sql" action="{{ database_url(database) }}{% if canned_query %}/{{ canned_query }}{% endif %}" method="get">
     <h3>Custom SQL query{% if display_rows %} returning {% if truncated %}more than {% endif %}{{ "{:,}".format(display_rows|length) }} row{% if display_rows|length == 1 %}{% else %}s{% endif %}{% endif %} <span class="show-hide-sql">{% if hide_sql %}(<a href="{{ path_with_removed_args(request, {'_hide_sql': '1'}) }}">show</a>){% else %}(<a href="{{ path_with_added_args(request, {'_hide_sql': '1'}) }}">hide</a>){% endif %}</span></h3>
     {% if not hide_sql %}
         {% if editable and config.allow_sql %}