diff --git a/bin/vyper b/bin/vyper
index 0bf2fc7f43..4e352a8ad0 100755
--- a/bin/vyper
+++ b/bin/vyper
@@ -12,20 +12,13 @@ from vyper.parser.parser import parse_to_lll
 from vyper.parser import parser_utils
 from vyper import compile_lll
 
+
 warnings.simplefilter('always')
 sys.tracebacklimit = 0
 tb_limit = os.environ.get('VYPER_TRACEBACK_LIMIT')
 if tb_limit:
     sys.tracebacklimit = int(tb_limit)
 
-parser = argparse.ArgumentParser(description='Vyper programming language for Ethereum')
-parser.add_argument('--version', action='version', version='{0}'.format(vyper.__version__))
-parser.add_argument('input_file', help='Vyper sourcecode to compile')
-parser.add_argument('-f', help='Format to print', default='bytecode', dest='format')
-parser.add_argument('--show-gas-estimates', help='Show gas estimates in ir output mode.', action="store_true")
-
-args = parser.parse_args()
-
 
 def uniq(seq):
     exists = set()
@@ -90,6 +83,14 @@ if __name__ == '__main__':
     output_format['source_map'] = get_source_map
     output_format['source_map_asm_list'] = get_source_map_asm_list
 
+    parser = argparse.ArgumentParser(description='Vyper programming language for Ethereum')
+    parser.add_argument('--version', action='version', version='{0}'.format(vyper.__version__))
+    parser.add_argument('input_file', help='Vyper sourcecode to compile')
+    parser.add_argument('-f', help='Format to print. Options: {}'.format(', '.join(output_format.keys())), default='bytecode', dest='format')
+    parser.add_argument('--show-gas-estimates', help='Show gas estimates in ir output mode.', action="store_true")
+
+    args = parser.parse_args()
+
     with open(args.input_file) as fh:
         code = fh.read()