diff --git a/src/aspeak/__main__.py b/src/aspeak/__main__.py
index 5499f50..58da34a 100644
--- a/src/aspeak/__main__.py
+++ b/src/aspeak/__main__.py
@@ -7,17 +7,18 @@
 parser = argparse.ArgumentParser(
     description='This program uses trial auth token of Azure Cognitive Services to do speech synthesis for you.',
     prog='aspeak')
-parser.add_argument('-V', '--version', action='version', version='%(prog)s 0.2.1')
 group = parser.add_mutually_exclusive_group()
-group.add_argument('-t', '--text', help='Text to speak. Left blank when reading from file/stdin.',
-                   dest='text', nargs='?', default=argparse.SUPPRESS)
-group.add_argument('-s', '--ssml', help='SSML to speak. Left blank when reading from file/stdin.',
-                   dest='ssml', nargs='?', default=argparse.SUPPRESS)
+group.add_argument('-V', '--version', action='version', version='%(prog)s 0.2.1')
+subgroup = group.add_mutually_exclusive_group()
+subgroup.add_argument('-t', '--text', help='Text to speak. Left blank when reading from file/stdin.',
+                      dest='text', nargs='?', default=argparse.SUPPRESS)
+subgroup.add_argument('-s', '--ssml', help='SSML to speak. Left blank when reading from file/stdin.',
+                      dest='ssml', nargs='?', default=argparse.SUPPRESS)
 parser.add_argument('-f', '--file', help='Text/SSML file to speak, default to `-`(stdin).', dest='file',
                     default=argparse.SUPPRESS)
 parser.add_argument('-o', '--output', help='Output wav file path', dest='output_path', default=None)
 parser.add_argument('-l', '--locale', help='Locale to use, default to en-US', dest='locale', default='en-US')
-parser.add_argument('-v', '--voice', help='Voice to use, default to en-US-JessaRUS', dest='voice', default=None)
+parser.add_argument('-v', '--voice', help='Voice to use.', dest='voice', default=None)
 
 
 def read_file(args):