diff --git a/marray/__init__.py b/marray/__init__.py
index 5ecaee9..d98ed8a 100644
--- a/marray/__init__.py
+++ b/marray/__init__.py
@@ -43,6 +43,7 @@ def __init__(self, data, mask=None):
             self._xp = xp
             self._sentinel = (info(self).max if not xp.isdtype(self.dtype, 'bool')
                               else None)
+            self.__array_namespace__ = mod
 
         @property
         def data(self):
@@ -172,7 +173,6 @@ def fun(self, other, name=name, **kwargs):
         setattr(MaskedArray, name, fun)
 
     # To be added
-    # __array_namespace__
     # __dlpack__, __dlpack_device__
     # to_device?
 
diff --git a/marray/tests/test_marray.py b/marray/tests/test_marray.py
index 661485e..eac4a5d 100644
--- a/marray/tests/test_marray.py
+++ b/marray/tests/test_marray.py
@@ -146,7 +146,7 @@ def irshift(x, y): x >>= y
                       'logaddexp', 'logical_and', 'logical_or', 'logical_xor',
                       'maximum', 'minimum', 'multiply', 'not_equal', 'pow',
                       'remainder', 'subtract']
-searching_array = ['argmax', 'argmin']
+searching_array = ['argmax', 'argmin']  # NumPy masked array funcs not good references
 statistical_array = ['cumulative_sum', 'max', 'mean',
                      'min', 'prod', 'std', 'sum', 'var']
 utility_array = ['all', 'any']
@@ -423,10 +423,13 @@ def test_statistical_array(f_name, keepdims, xp=np, dtype='float64', seed=None):
 # Manipulation functions (apply to data and mask separately)
 
 #?
-# Searching functions - finish testing argmin/argmax with above
+# Searching functions - would test argmin/argmax with statistical functions,
+#                       but NumPy masked version isn't correct
 # Set functions
 # Sorting functions
+# __array_namespace__
 
 def test_test():
-    seed = 8377009968503871097350278305436713931
+    seed = 149020664425889521094089537542803361848
+    # test_statistical_array('argmin', True, seed=seed)
     test_rarithmetic_binary(arithmetic_binary[0], 'float32', seed=seed)