diff --git a/tupak/gw/detector.py b/tupak/gw/detector.py
index 4a479a90225e2f84b1ee8dbf8d1879328de1326f..842fc37333a9b1a1f538f23f8cd90e1de0736b84 100644
--- a/tupak/gw/detector.py
+++ b/tupak/gw/detector.py
@@ -305,8 +305,9 @@ class InterferometerStrainData(object):
     @property
     def maximum_frequency(self):
         """ Force the maximum frequency be less than the Nyquist frequency """
-        if 2 * self.__maximum_frequency > self.sampling_frequency:
-            self.__maximum_frequency = self.sampling_frequency / 2.
+        if self.sampling_frequency is not None:
+            if 2 * self.__maximum_frequency > self.sampling_frequency:
+                self.__maximum_frequency = self.sampling_frequency / 2.
         return self.__maximum_frequency
 
     @maximum_frequency.setter