diff --git a/bin/genpw b/bin/genpw
index cce1d68..eb8b87f 100755
--- a/bin/genpw
+++ b/bin/genpw
@@ -1,37 +1,38 @@
 #!/usr/bin/env python
-"""Module to generate a random string
+"""
+Module to generate a random string
 
 Attributes:
     LENGTH (int): Defaults to a length of 16
 """
 
-import sys
-import optparse
-import os
+import argparse
 import base64
+import os
+import sys
 
 LENGTH = 16
 
 
-def generate(length):
+def generate(length: int) -> str:
     """Simple function to call OpenSSL
 
     Args:
         length (int): length of string to return
     """
-    return base64.encodestring(os.urandom(256))[:length]
-
-
-def main():
-    """Main function to call
-    """
-    parser = optparse.OptionParser()
-    parser.add_option('-n', dest='length', default=LENGTH, type=int)
-    opts, _ = parser.parse_args()
-
-    sys.stdout.write(generate(opts.length))
+    return base64.encodebytes(os.urandom(256)).decode()[:length]
 
 
 if __name__ == '__main__':
-    main()
-    sys.exit(0)
+
+    def main() -> int:
+        """Main function to call"""
+        parser = argparse.ArgumentParser()
+        parser.add_argument('-n', dest='length', default=LENGTH, type=int)
+        args = parser.parse_args()
+
+        sys.stdout.write(generate(args.length))
+
+        return 0
+
+    sys.exit(main())