diff --git a/app/models/workshop.rb b/app/models/workshop.rb
index 370159504..87056605c 100644
--- a/app/models/workshop.rb
+++ b/app/models/workshop.rb
@@ -1,4 +1,6 @@
 class Workshop < ApplicationRecord
+  self.ignored_columns += %w[sign_up_url]
+
   include DateTimeConcerns
   include Invitable
   include CheckInable
diff --git a/spec/models/workshop_spec.rb b/spec/models/workshop_spec.rb
index c5078d522..5746e75f3 100644
--- a/spec/models/workshop_spec.rb
+++ b/spec/models/workshop_spec.rb
@@ -415,4 +415,10 @@
       expect(workshop.cancellations_open?).to be(false)
     end
   end
+
+  describe 'legacy columns' do
+    it 'does not expose the legacy sign_up_url attribute' do
+      expect(described_class.new).not_to respond_to(:sign_up_url)
+    end
+  end
 end