diff --git a/blimpy/io/hdf_reader.py b/blimpy/io/hdf_reader.py
index 87d5bef..c7ff8fa 100644
--- a/blimpy/io/hdf_reader.py
+++ b/blimpy/io/hdf_reader.py
@@ -16,7 +16,7 @@ def __init__(self, filename, f_start=None, f_stop=None, t_start=None, t_stop=Non
         """ Constructor.
 
         Args:
-            filename (str): filename of blimpy file.
+            filename (str): file path of HDF5 file.
             f_start (float): start frequency, in MHz
             f_stop (float): stop frequency, in MHz
             t_start (int): start time bin