diff --git a/pycbc/types/array.py b/pycbc/types/array.py
index <HASH>..<HASH> 100644
--- a/pycbc/types/array.py
+++ b/pycbc/types/array.py
@@ -556,7 +556,7 @@ class Array(object):
         """ Used internally by SWIG typemaps to ensure @_convert is called and scheme is correct  """
 
         if type(self._data) is not _numpy.ndarray:
-            raise TypeError("Cannot call LAL function from the GPU")
+            raise NotImplementedError("Cannot call LAL function from the GPU")
         else:
             return self;
Change error for Array._swighelper to NotImplemented