diff --git a/lib/annotate/annotate_models.rb b/lib/annotate/annotate_models.rb
index dc2901a3..c87cc4bc 100644
--- a/lib/annotate/annotate_models.rb
+++ b/lib/annotate/annotate_models.rb
@@ -107,7 +107,7 @@ def quote(value)
       when BigDecimal               then value.to_s('F')
       when Array                    then value.map { |v| quote(v) }
       else
-        value.inspect
+        value.respond_to?(:to_s) ? value.to_s.inspect : value.inspect
       end
     end
 
diff --git a/spec/lib/annotate/annotate_models_spec.rb b/spec/lib/annotate/annotate_models_spec.rb
index 09647461..46d395ba 100644
--- a/spec/lib/annotate/annotate_models_spec.rb
+++ b/spec/lib/annotate/annotate_models_spec.rb
@@ -152,6 +152,20 @@ def mock_column(name, type, options = {})
         is_expected.to eq(['1.2'])
       end
     end
+
+    context 'when the argument is an object that responds to to_s' do
+      let(:value) do
+        obj = Object.new
+        def obj.to_s
+          "custom string representation"
+        end
+        obj
+      end
+
+      it 'returns the result of to_s wrapped in quotes' do
+        is_expected.to eq('"custom string representation"')
+      end
+    end
   end
 
   describe '.parse_options' do