diff --git a/app/models/category.rb b/app/models/category.rb
index d36d490ace9..07b890e0644 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -25,7 +25,7 @@ class Category < ActiveRecord::Base
   register_custom_field_type(REQUIRE_REPLY_APPROVAL, :boolean)
   register_custom_field_type(NUM_AUTO_BUMP_DAILY, :integer)
 
-  belongs_to :topic, dependent: :destroy
+  belongs_to :topic
   belongs_to :topic_only_relative_url,
               -> { select "id, title, slug" },
               class_name: "Topic",
@@ -67,6 +67,7 @@ class Category < ActiveRecord::Base
   validates :slug, exclusion: { in: RESERVED_SLUGS }
 
   after_create :create_category_definition
+  after_destroy :trash_category_definition
 
   before_save :apply_permissions
   before_save :downcase_email
@@ -296,6 +297,10 @@ class Category < ActiveRecord::Base
     end
   end
 
+  def trash_category_definition
+    self.topic&.trash!
+  end
+
   def topic_url
     if has_attribute?("topic_slug")
       Topic.relative_url(topic_id, read_attribute(:topic_slug))
diff --git a/spec/models/category_spec.rb b/spec/models/category_spec.rb
index 63c38499030..8668da467cd 100644
--- a/spec/models/category_spec.rb
+++ b/spec/models/category_spec.rb
@@ -538,7 +538,7 @@ describe Category do
     it 'is deleted correctly' do
       @category.destroy
       expect(Category.exists?(id: @category_id)).to be false
-      expect(Topic.exists?(id: @topic_id)).to be false
+      expect(Topic.with_deleted.where.not(deleted_at: nil).exists?(id: @topic_id)).to be true
       expect(SiteSetting.shared_drafts_category).to be_blank
     end