diff --git a/wsme/tests/test_api.py b/wsme/tests/test_api.py
index 4157acf..a64cbff 100644
--- a/wsme/tests/test_api.py
+++ b/wsme/tests/test_api.py
@@ -191,10 +191,15 @@ class TestController(unittest.TestCase):
                 return a * b
 
             mul_int = expose(int, int, int, wrap=True)(multiply)
+
             mul_float = expose(
                 float, float, float,
                 wrap=True)(multiply)
 
+            mul_string = expose(
+                wsme.types.text, wsme.types.text, int,
+                wrap=True)(multiply)
+
         r = MyRoot(['restjson'])
 
         app = webtest.TestApp(r.wsgiapp())
@@ -211,6 +216,12 @@ class TestController(unittest.TestCase):
 
         self.assertEquals(res.body, '8.8')
 
+        res = app.get('/mul_string?a=hello&b=2', headers={
+            'Accept': 'application/json'
+        })
+
+        self.assertEquals(res.body, '"hellohello"')
+
 
 class TestFunctionDefinition(unittest.TestCase):