diff --git a/plinth/modules/tor/__init__.py b/plinth/modules/tor/__init__.py
index f97e78307..a33b34e19 100644
--- a/plinth/modules/tor/__init__.py
+++ b/plinth/modules/tor/__init__.py
@@ -167,9 +167,9 @@ def diagnose():
     ])
     if 'orport' in ports:
         results.append(
-            action_utils.diagnose_port_listening(ports['orport'], 'tcp4'))
+            action_utils.diagnose_port_listening(int(ports['orport']), 'tcp4'))
         results.append(
-            action_utils.diagnose_port_listening(ports['orport'], 'tcp6'))
+            action_utils.diagnose_port_listening(int(ports['orport']), 'tcp6'))
 
     results.append([
         _('Obfs3 transport registered'),
@@ -177,7 +177,7 @@ def diagnose():
     ])
     if 'obfs3' in ports:
         results.append(
-            action_utils.diagnose_port_listening(ports['obfs3'], 'tcp4'))
+            action_utils.diagnose_port_listening(int(ports['obfs3']), 'tcp4'))
 
     results.append([
         _('Obfs4 transport registered'),
@@ -185,7 +185,7 @@ def diagnose():
     ])
     if 'obfs4' in ports:
         results.append(
-            action_utils.diagnose_port_listening(ports['obfs4'], 'tcp4'))
+            action_utils.diagnose_port_listening(int(ports['obfs4']), 'tcp4'))
 
     results.append(_diagnose_url_via_tor('http://www.debian.org', '4'))
     results.append(_diagnose_url_via_tor('http://www.debian.org', '6'))