diff --git a/speedtest.py b/speedtest.py
index 7a99c99..82edf59 100755
--- a/speedtest.py
+++ b/speedtest.py
@@ -1626,7 +1626,7 @@ def parse_args():
                         action='store_const', const=False,
                         help='Do not perform upload test')
     parser.add_argument('--bytes', dest='units', action='store_const',
-                        const=('byte', 8), default=('bit', 1),
+                        const=('Byte', 8), default=('bit', 1),
                         help='Display values in bytes instead of bits. Does '
                              'not affect the image generated by --share, nor '
                              'output from --json or --csv')