diff --git a/static/themes/default/css/main.css b/static/themes/default/css/main.css
index 8179a3ba0..cc61c8c77 100644
--- a/static/themes/default/css/main.css
+++ b/static/themes/default/css/main.css
@@ -128,6 +128,29 @@ h6:not(:first-child) {
     color: #737373;
 }
 
+/* .close was renamed to .alert-dismissable.btn-close in Bootstrap 5, needs
+   updated django-bootstrap-from */
+form .alert {
+    padding-right: 3rem;
+}
+
+form .alert .close {
+    position: absolute;
+    top: 0;
+    right: 0;
+    z-index: 2;
+    padding: 1.25rem 1rem;
+    cursor: pointer;
+    color: transparent;
+    box-sizing: content-box;
+    width: 1em;
+    height: 1em;
+    background: transparent url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23000'%3e%3cpath d='M.293.293a1 1 0 0 1 1.414 0L8 6.586 14.293.293a1 1 0 1 1 1.414 1.414L9.414 8l6.293 6.293a1 1 0 0 1-1.414 1.414L8 9.414l-6.293 6.293a1 1 0 0 1-1.414-1.414L6.586 8 .293 1.707a1 1 0 0 1 0-1.414z'/%3e%3c/svg%3e") center/1em auto no-repeat;
+    border: 0;
+    border-radius: 0.375rem;
+    opacity: 0.5;
+}
+
 /* Disabled form elements show as gray, removed in Bootstrap 5 */
 .form-control:disabled, .form-control[readonly] {
     background-color: var(--freedombox-form-disabled-bg-color);