diff --git a/extensions/tags/bootstrap.php b/extensions/tags/bootstrap.php
index c13aa6aaf..535c5dcfe 100644
--- a/extensions/tags/bootstrap.php
+++ b/extensions/tags/bootstrap.php
@@ -27,8 +27,4 @@ return function (Dispatcher $events) {
     $events->subscribe(Access\DiscussionPolicy::class);
     $events->subscribe(Access\TagPolicy::class);
     $events->subscribe(Access\FlagPolicy::class);
-
-    Tag::saving(function ($model) {
-        $this->app->make('Flarum\Tags\TagValidator')->assertValid($model);
-    });
 };
diff --git a/extensions/tags/js/admin/src/components/EditTagModal.js b/extensions/tags/js/admin/src/components/EditTagModal.js
index 317835256..a38022363 100644
--- a/extensions/tags/js/admin/src/components/EditTagModal.js
+++ b/extensions/tags/js/admin/src/components/EditTagModal.js
@@ -101,9 +101,9 @@ export default class EditTagModal extends Modal {
       isHidden: this.isHidden()
     }).then(
       () => this.hide(),
-      () => {
+      response => {
         this.loading = false;
-        m.redraw();
+        this.handleErrors(response);
       }
     );
   }
diff --git a/extensions/tags/migrations/2015_10_19_061223_make_slug_unique.php b/extensions/tags/migrations/2015_10_19_061223_make_slug_unique.php
new file mode 100644
index 000000000..4d152cde5
--- /dev/null
+++ b/extensions/tags/migrations/2015_10_19_061223_make_slug_unique.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Flarum\Tags\Migration;
+
+use Flarum\Database\AbstractMigration;
+use Illuminate\Database\Schema\Blueprint;
+
+class MakeSlugUnique extends AbstractMigration
+{
+    public function up()
+    {
+        $this->schema->table('tags', function (Blueprint $table) {
+            $table->unique('slug');
+        });
+    }
+
+    public function down()
+    {
+        $this->schema->table('tags', function (Blueprint $table) {
+            $table->dropUnique('tags_slug_unique');
+        });
+    }
+}
diff --git a/extensions/tags/src/Command/CreateTagHandler.php b/extensions/tags/src/Command/CreateTagHandler.php
index 2de29769b..a0c88f896 100644
--- a/extensions/tags/src/Command/CreateTagHandler.php
+++ b/extensions/tags/src/Command/CreateTagHandler.php
@@ -12,11 +12,25 @@ namespace Flarum\Tags\Command;
 
 use Flarum\Core\Access\AssertPermissionTrait;
 use Flarum\Tags\Tag;
+use Flarum\Tags\TagValidator;
 
 class CreateTagHandler
 {
     use AssertPermissionTrait;
 
+    /**
+     * @var TagValidator
+     */
+    protected $validator;
+
+    /**
+     * @param TagValidator $validator
+     */
+    public function __construct(TagValidator $validator)
+    {
+        $this->validator = $validator;
+    }
+
     /**
      * @param CreateTag $command
      * @return Tag
@@ -36,6 +50,8 @@ class CreateTagHandler
             array_get($data, 'attributes.isHidden')
         );
 
+        $this->validator->assertValid($tag->getAttributes());
+
         $tag->save();
 
         return $tag;
diff --git a/extensions/tags/src/Command/EditTagHandler.php b/extensions/tags/src/Command/EditTagHandler.php
index b1ea2ef28..d4a335109 100644
--- a/extensions/tags/src/Command/EditTagHandler.php
+++ b/extensions/tags/src/Command/EditTagHandler.php
@@ -12,6 +12,7 @@ namespace Flarum\Tags\Command;
 
 use Flarum\Core\Access\AssertPermissionTrait;
 use Flarum\Tags\TagRepository;
+use Flarum\Tags\TagValidator;
 
 class EditTagHandler
 {
@@ -23,11 +24,18 @@ class EditTagHandler
     protected $tags;
 
     /**
-     * @param TagRepository $tags
+     * @var TagValidator
      */
-    public function __construct(TagRepository $tags)
+    protected $validator;
+
+    /**
+     * @param TagRepository $tags
+     * @param TagValidator $validator
+     */
+    public function __construct(TagRepository $tags, TagValidator $validator)
     {
         $this->tags = $tags;
+        $this->validator = $validator;
     }
 
     /**
@@ -70,6 +78,8 @@ class EditTagHandler
             $tag->is_restricted = (bool) $attributes['isRestricted'];
         }
 
+        $this->validator->assertValid($tag->getDirty());
+
         $tag->save();
 
         return $tag;
diff --git a/extensions/tags/src/TagValidator.php b/extensions/tags/src/TagValidator.php
index 3411f5d17..63b8c946a 100644
--- a/extensions/tags/src/TagValidator.php
+++ b/extensions/tags/src/TagValidator.php
@@ -19,6 +19,6 @@ class TagValidator extends AbstractValidator
      */
     protected $rules = [
         'name' => ['required'],
-        'slug' => ['required', 'unique:slug']
+        'slug' => ['required', 'unique:tags']
     ];
 }