diff --git a/madarrays/waveform.py b/madarrays/waveform.py
index 40e8f5873c0a0803679b44d05a201b1657977b3d..c323293bfc65ec61e90cb9fadb6d4019187b77df 100644
--- a/madarrays/waveform.py
+++ b/madarrays/waveform.py
@@ -135,7 +135,7 @@ class Waveform(MadArray):
         See :class:`MadArray`.
     """
 
-    def __new__(cls, data, mask=None, fs=None,  masked_indexing=None):
+    def __new__(cls, data, fs=None, mask=None, masked_indexing=None):
         if fs is None:
             if isinstance(data, Waveform):
                 fs = data.fs