diff --git a/format_novel/format_novel.py b/format_novel/format_novel.py
index 64889e0..a4eb831 100755
--- a/format_novel/format_novel.py
+++ b/format_novel/format_novel.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python
 
+import argparse
 import sys
 
 import docx
@@ -73,9 +74,20 @@ def double_space_and_indent(paragraphs):
         previous_paragraph_plaintext = this_paragraph_plaintext
 
 
+def parse_arguments(unparsed_arguments):
+    parser = argparse.ArgumentParser(add_help=True)
+    parser.add_argument(
+        metavar='FILENAME',
+        dest='document_filename',
+        help='Novel document to format',
+    )
+
+    parser.parse_args(unparsed_arguments)
+
+
 def main():
-    document_filename = sys.argv[1]
-    document = docx.Document(document_filename)
+    arguments = parse_arguments(sys.argv[1:])
+    document = docx.Document(arguments.document_filename)
 
     set_default_font(document)
     # add_header_text(document, 'Author / Project Title / ')
@@ -84,7 +96,7 @@ def main():
     right_align_header(document)
     double_space_and_indent(document.paragraphs)
 
-    document.save(document_filename)
+    document.save(arguments.document_filename)
 
 
 if __name__ == '__main__':