@@ -623,6 +623,10 @@ def __reduce__(self):
                 (self.__class__, np.ndarray, (0, ), 'b', ),
                 self.__getstate__())
 
+    def __deepcopy__(self, memo_dict):
+        # constructor copies by default
+        return Quantity(self.magnitude, self.dimensionality)
+
 
 def _reconstruct_quantity(subtype, baseclass, baseshape, basetype,):
     """Internal function that builds a new MaskedArray from the