diff --git a/composer.json b/composer.json
index fb7e942..ce2dd9e 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
     "name": "dashboard/unifi",
     "description": "UniFi network management, WiFi stats, and captive portal authentication for the Dashboard platform",
-    "version": "1.13.3",
+    "version": "1.13.4",
     "type": "library",
     "license": "MIT",
     "autoload": {
diff --git a/src/Http/Controllers/PortalController.php b/src/Http/Controllers/PortalController.php
index c970038..3501c13 100644
--- a/src/Http/Controllers/PortalController.php
+++ b/src/Http/Controllers/PortalController.php
@@ -36,7 +36,11 @@ class PortalController extends Controller
             'match_value'     => 'required|string|max:255',
             'vlan_id'         => 'required|integer|min:1|max:4094',
             'max_devices'     => 'required|integer|min:1|max:50',
-            'session_minutes' => 'required|integer|min:1',
+            // Bounded by the column that stores it: unifi_vlan_mappings.session_minutes
+            // is unsignedInteger, so an unbounded value reached the INSERT and raised
+            // SQLSTATE 22003 — a 500 where a validation error belongs (central-unifi#5).
+            // 525600 minutes is a year, far more session than anyone will ever grant.
+            'session_minutes' => 'required|integer|min:1|max:525600',
         ]);
         $data['sort_order'] = VlanMapping::max('sort_order') + 1;
         VlanMapping::create($data);
@@ -51,7 +55,11 @@ class PortalController extends Controller
             'match_value'     => 'required|string|max:255',
             'vlan_id'         => 'required|integer|min:1|max:4094',
             'max_devices'     => 'required|integer|min:1|max:50',
-            'session_minutes' => 'required|integer|min:1',
+            // Bounded by the column that stores it: unifi_vlan_mappings.session_minutes
+            // is unsignedInteger, so an unbounded value reached the INSERT and raised
+            // SQLSTATE 22003 — a 500 where a validation error belongs (central-unifi#5).
+            // 525600 minutes is a year, far more session than anyone will ever grant.
+            'session_minutes' => 'required|integer|min:1|max:525600',
         ]);
         $mapping->update($data);
         return back()->with('success', 'Mapping updated.');