diff --git a/website_form_builder/static/src/css/website_form_builder.less b/website_form_builder/static/src/css/website_form_builder.less
index cd4155fd32..829f7fb298 100644
--- a/website_form_builder/static/src/css/website_form_builder.less
+++ b/website_form_builder/static/src/css/website_form_builder.less
@@ -15,10 +15,12 @@
     }
 }
 
-body .modal.o_website_modal {
+/* Make modals with multiselect with a usable height */
+body .modal.o_technical_modal {
     textarea, select[multiple] {
         &.form-control {
             height: auto;
+            background: None;
         }
     }
 }
diff --git a/website_form_builder/static/src/xml/widgets.xml b/website_form_builder/static/src/xml/widgets.xml
index 22cb731fee..ca5018aade 100644
--- a/website_form_builder/static/src/xml/widgets.xml
+++ b/website_form_builder/static/src/xml/widgets.xml
@@ -13,7 +13,7 @@
         <form>
             <div class="form-group">
                 <label for="field">Choose the new field for the form</label>
-                <select id="field" class="form-control" multiple="">
+                <select id="field" class="form-control" multiple="1" size="6">
                     <t t-foreach="widget.sorted_fields()" t-as="field_pair">
                         <option t-att-value="field_pair[1]">
                             <t t-esc="field_pair[0]"/>