diff --git a/crispy_bootstrap5/templates/bootstrap5/accordion.html b/crispy_bootstrap5/templates/bootstrap5/accordion.html
index 383ea2d..98e6618 100644
--- a/crispy_bootstrap5/templates/bootstrap5/accordion.html
+++ b/crispy_bootstrap5/templates/bootstrap5/accordion.html
@@ -1,3 +1,3 @@
-<div class="accordion{% if accordion.flush %} accordion-flush{% endif %}" id="{{ accordion.css_id }}">
+<div class="accordion{% if accordion.flush %} accordion-flush{% endif %}{% if accordion.css_class %} {{accordion.css_class}}{% endif %}" id="{{ accordion.css_id }}">
     {{ content|safe }}
 </div>
diff --git a/tests/test_layout_objects.py b/tests/test_layout_objects.py
index 72b3cd8..3a8fc35 100644
--- a/tests/test_layout_objects.py
+++ b/tests/test_layout_objects.py
@@ -274,6 +274,25 @@ def test_accordion_and_accordiongroup(self):
         )
         assert parse_form(form) == parse_expected("accordion.html")
 
+    def test_accordion_css_class_is_applied_to_accordion(self):
+        classes = 'one two three'
+        test_form = SampleForm()
+        test_form.helper = FormHelper()
+        test_form.helper.form_tag = False
+        test_form.helper.layout = Layout(
+            Accordion(
+                AccordionGroup("one", "first_name"),
+                css_class=classes,
+                css_id='super-accordion'
+            )
+        )
+        html = render_crispy_form(test_form)
+
+        assert (
+            html.count('<div class="accordion %s" id="super-accordion"' % classes)
+            == 1
+        )
+
     def test_accordion_active_false_not_rendered(self):
         test_form = SampleForm()
         test_form.helper = FormHelper()