Fixed #2776 -- added an FAQ on compilation errors on OS X
diff --git a/docs/faq.rst b/docs/faq.rst
index 10c8656..66a775a 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -16,3 +16,12 @@
.. _`NaCl`: https://nacl.cr.yp.to/
.. _`PyNaCl`: https://pynacl.readthedocs.org
+
+Compiling ``cryptography`` on OS X produces a ``fatal error: 'openssl/aes.h' file not found`` error
+----------------------------------------------------------------------------------------------------
+
+This happens because OS X 10.11 no longer includes a copy of OpenSSL.
+``cryptography`` now provides wheels which include a statically linked copy of
+OpenSSL. You're seeing this error because your copy of pip is too old to find
+our wheel files. Upgrade your copy of pip with ``pip install -U pip`` and then
+try install ``cryptography`` again.