diff --git a/README.md b/README.md
index f335670..b0dd613 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,16 @@ you want to report a security bug. That way the next person having the
 same problem can benefit from the time spent solving the problem the
 first time.
 
+System Requirements
+-------------------
+
+This project depends on Python 2.7 and the Python mercurial package.
+If Python is not installed, install it before proceeding.  The
+mercurial package can be installed with `pip install mercurial`.
+
+If you're on Windows, run the following commands in git bash (Git for
+Windows).
+
 Usage
 -----