diff --git a/README.md b/README.md
index 74c1d1f..045ec10 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # slideslurp
 
 Give slideslurp a URL to a [SlideShare](https://www.slideshare.net/)
-presentation and it will give you a PDF called `out.pdf`.
+presentation and it will render it as a PDF.
 
 I will clean this up, I promise.
 
@@ -11,5 +11,21 @@ I will clean this up, I promise.
 pip install slideslurp
 ```
 
+## Usage
+
+```
+usage: slideslurp [-h] [--output OUTPUT] url
+
+Generate PDFs from Slideshare presentations
+
+positional arguments:
+  url                   the URL to slurp
+
+optional arguments:
+  -h, --help            show this help message and exit
+  --output OUTPUT, -o OUTPUT
+                        the file to write to (default: out.pdf)
+```
+
 <hr/>
 Happy slurping!
diff --git a/setup.py b/setup.py
index 72fad80..3fa0075 100644
--- a/setup.py
+++ b/setup.py
@@ -6,13 +6,13 @@ from setuptools import setup
 
 setup(
     name = 'slideslurp',
-    version = '0.0.3',
+    version = '0.0.4',
     description = 'SlideShare to PDF',
     author = 'Veit Heller',
     author_email = 'veit@veitheller.de',
     license = 'MIT License',
     url = 'https://github.com/hellerve/slideslurp',
-    download_url = 'https://github.com/hellerve/slideslurp/tarball/0.0.3',
+    download_url = 'https://github.com/hellerve/slideslurp/tarball/0.0.4',
     packages = find_packages('.'),
     install_requires=[
         "bs4",
diff --git a/slideslurp/__init__.py b/slideslurp/__init__.py
index ce83fc6..04638c9 100644
--- a/slideslurp/__init__.py
+++ b/slideslurp/__init__.py
@@ -1,3 +1,4 @@
+import argparse
 import sys
 
 import bs4
@@ -6,16 +7,25 @@ import requests
 from reportlab.pdfgen import canvas
 
 
-def main():
-    if not len(sys.argv) == 2:
-        print("Usage: slideslurp <url>")
-        sys.exit(1)
-    url = sys.argv[1]
+def parse_args():
+    descr = "Generate PDFs from Slideshare presentations"
 
-    res = requests.get(url)
+    parser = argparse.ArgumentParser(description=descr)
+    parser.add_argument('url', metavar='url', nargs=1,
+                        help='the URL to slurp')
+    parser.add_argument('--output', '-o', default='out.pdf',
+                        help='the file to write to (default: out.pdf)')
+
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    res = requests.get(args.url)
 
     tree = bs4.BeautifulSoup(res.text, "html.parser")
-    c = canvas.Canvas('out.pdf')
+    c = canvas.Canvas(args.file)
 
     for img in tree.findAll("img", class_="slide_image"):
         img_url = img.attrs["data-full"]