diff --git a/lib/split/helper.rb b/lib/split/helper.rb
index 3fc74a47..163280f3 100644
--- a/lib/split/helper.rb
+++ b/lib/split/helper.rb
@@ -29,7 +29,8 @@ def ab_test(metric_descriptor, control = nil, *alternatives)
       end
 
       if block_given?
-        yield(alternative, (trial.metadata if trial))
+        metadata = trial ? trial.metadata : {}
+        yield(alternative, metadata)
       else
         alternative
       end
diff --git a/spec/helper_spec.rb b/spec/helper_spec.rb
index 2846eb5b..564236d0 100755
--- a/spec/helper_spec.rb
+++ b/spec/helper_spec.rb
@@ -216,6 +216,17 @@
         meta
       end).to eq('Meta1')
     end
+
+    it 'should pass empty hash to helper block if library disabled' do
+      Split.configure do |config|
+        config.enabled = false
+      end
+
+      expect(ab_test('my_experiment')).to eq 'one'
+      expect(ab_test('my_experiment') do |_, meta|
+        meta
+      end).to eq({})
+    end
   end
 
   describe 'finished' do