diff --git a/lib/App/Netdisco/Web/Plugin/AdminTask/PseudoDevice.pm b/lib/App/Netdisco/Web/Plugin/AdminTask/PseudoDevice.pm
index bf4b9d38..15d3f15d 100644
--- a/lib/App/Netdisco/Web/Plugin/AdminTask/PseudoDevice.pm
+++ b/lib/App/Netdisco/Web/Plugin/AdminTask/PseudoDevice.pm
@@ -73,9 +73,19 @@ ajax '/ajax/control/admin/pseudodevice/update' => require_role admin => sub {
       }
       elsif (param('ports') < $count) {
           my $start = param('ports') + 1;
-          $device->ports
-            ->single({port => "Port$_"})->delete
-          for ($start .. $count);
+
+          foreach my $port ($start .. $count) {
+              $device->ports
+                ->single({port => "Port${port}"})->delete;
+
+              # clear outdated manual topology links
+              schema('netdisco')->resultset('Topology')->search({
+                -or => [
+                  { dev1 => $device->ip, port1 => "Port${port}" },
+                  { dev2 => $device->ip, port2 => "Port${port}" },
+                ],
+              })->delete;
+          }
       }
     });
 };