diff --git a/actions/ldap b/actions/ldap
index fd06bce54..cf0dc75eb 100755
--- a/actions/ldap
+++ b/actions/ldap
@@ -121,17 +121,6 @@ remove_user_from_group()
 }
 
 
-diagnose()
-{
-    result="failed"
-    if lsldap | grep 'dn: dc=thisbox' > /dev/null; then
-        result="passed"
-    fi
-
-    echo "[[\"Access LDAP server locally\", \"$result\"]]"
-}
-
-
 setup()
 {
     # XXX: Password setting on users is disabled as changing passwords
@@ -174,9 +163,6 @@ case $command in
     remove-user-from-group)
         remove_user_from_group "$@"
     ;;
-    diagnose)
-        diagnose "$@"
-    ;;
     *)
         echo "Invalid sub-command"
         exit -1
diff --git a/plinth/modules/users/__init__.py b/plinth/modules/users/__init__.py
index 45b7a9906..6977066c2 100644
--- a/plinth/modules/users/__init__.py
+++ b/plinth/modules/users/__init__.py
@@ -21,9 +21,11 @@ Plinth module to manage users
 
 from gettext import gettext as _
 import json
+import subprocess
 
 from plinth import cfg
 from plinth import actions
+from plinth import action_utils
 
 depends = ['plinth.modules.system']
 
@@ -36,6 +38,31 @@ def init():
 
 
 def diagnose():
-    """Run diagnostics and result the results."""
-    output = actions.superuser_run('ldap', ['diagnose'])
-    return json.loads(output)
+    """Run diagnostics and return the results."""
+    results = []
+
+    results.append(action_utils.diagnose_port_listening(389, 'tcp4'))
+    results.append(action_utils.diagnose_port_listening(389, 'tcp6'))
+
+    results.append(_diagnose_ldap_entry('dc=thisbox'))
+    results.append(_diagnose_ldap_entry('ou=people'))
+    results.append(_diagnose_ldap_entry('ou=groups'))
+
+    return results
+
+
+def _diagnose_ldap_entry(search_item):
+    """Diagnose that an LDAP entry exists."""
+    result = 'failed'
+
+    try:
+        subprocess.check_output(['ldapsearch', '-x', '-b', 'dc=thisbox',
+                                 search_item])
+        result = 'passed'
+    except subprocess.CalledProcessError:
+        pass
+
+    return [_('Check LDAP entry "{search_item}"')
+            .format(search_item=search_item), result]
+
+
diff --git a/plinth/modules/users/templates/users_list.html b/plinth/modules/users/templates/users_list.html
index 29933d5aa..5bec38ef8 100644
--- a/plinth/modules/users/templates/users_list.html
+++ b/plinth/modules/users/templates/users_list.html
@@ -60,8 +60,7 @@
         {% endfor %}
       </div>
 
-      <a href="{% url 'diagnostics:module' 'users' %}"
-         class="btn btn-default">Run Diagnostics</a>
+      {% include "diagnostics_button.html" with module="users" %}
     </div>
   </div>