diff --git a/setup.py b/setup.py
index c9962fe..51779e7 100644
--- a/setup.py
+++ b/setup.py
@@ -18,6 +18,9 @@ PDF parser that can be used for other purposes instead of text analysis.''',
     author='Yusuke Shinyama',
     author_email='yusuke at cs dot nyu dot edu',
     url='http://euske.github.io/pdfminer/index.html',
+    install_requires=[
+    'pycrypto',
+    ],
     packages=[
     'pdfminer',
     ],