diff --git a/test/string_calculator_test.dart b/test/string_calculator_test.dart
index fd7ceba..d48b197 100644
--- a/test/string_calculator_test.dart
+++ b/test/string_calculator_test.dart
@@ -9,6 +9,8 @@ void main() {
       calculator = StringCalculator();
     });
 
-    // Tests will be added as we hunt bugs
+    test('empty string returns 0', () {
+      expect(calculator.add(''), equals(0));
+    });
   });
 }