diff --git a/spec/unit/rom/gateway_spec.rb b/spec/unit/rom/gateway_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/unit/rom/gateway_spec.rb
+++ b/spec/unit/rom/gateway_spec.rb
@@ -107,4 +107,11 @@ describe ROM::Gateway do
     end
   end
 
+  describe '#extend_command_class' do
+    it 'returns the class sent as 1st parameter' do
+      klass = ROM::Relation
+
+      expect(gateway.extend_command_class(klass, "foo")).to eq(klass)
+    end
+  end
 end
Test Gateway#extend_command_class