diff --git a/astropy/io/fits/hdu/base.py b/astropy/io/fits/hdu/base.py
index a034fb6feb0..d543fe1b7f9 100644
--- a/astropy/io/fits/hdu/base.py
+++ b/astropy/io/fits/hdu/base.py
@@ -306,7 +306,7 @@ def fromstring(cls, data, checksum=False, ignore_missing_end=False, **kwargs):
 
         Parameters
         ----------
-        data : str, bytearray, memoryview, ndarray
+        data : str, bytes, memoryview, ndarray
             A byte string containing the HDU's header and data.
 
         checksum : bool, optional