diff --git a/plinth/modules/diagnostics/templates/diagnostics.html b/plinth/modules/diagnostics/templates/diagnostics.html
index 082d3a761..93809d582 100644
--- a/plinth/modules/diagnostics/templates/diagnostics.html
+++ b/plinth/modules/diagnostics/templates/diagnostics.html
@@ -35,7 +35,7 @@
 {% block configuration %}
 
   {% if not is_running %}
-    <form class="form form-diagnostics-button" method="post"
+    <form class="form form-run-diagnostics" method="post"
           action="{% url 'diagnostics:index' %}">
       {% csrf_token %}