diff --git a/test/calibration_tests.py b/test/calibration_tests.py
index 1c89f79b0a5af501a998b0c5bfa3b4e3e678b724..a916c841a90b63fd8fcab6f25ef3644ffa95a822 100644
--- a/test/calibration_tests.py
+++ b/test/calibration_tests.py
@@ -12,8 +12,9 @@ class TestBaseClass(unittest.TestCase):
         del self.model
 
     def test_repr(self):
-        expected = 'Recalibrate(prefix={})'.format('recalib_')
+        expected = 'Recalibrate(prefix={})'.format('\'recalib_\'')
         actual = repr(self.model)
+        print(expected)
         self.assertEqual(expected, actual)
 
     def test_calibration_factor(self):
diff --git a/tupak/gw/calibration.py b/tupak/gw/calibration.py
index 2c701593fbee4968c3c58c66978201d99d75ca14..7460eb424db95e584e51a8b34ee06c3b54915dcb 100644
--- a/tupak/gw/calibration.py
+++ b/tupak/gw/calibration.py
@@ -22,7 +22,7 @@ class Recalibrate(object):
         self.prefix = prefix
 
     def __repr__(self):
-        return self.__class__.__name__ + '(prefix={})'.format(self.prefix)
+        return self.__class__.__name__ + '(prefix=\'{}\')'.format(self.prefix)
 
     def get_calibration_factor(self, frequency_array, **params):
         """Apply calibration model