add PBKDF2HMAC to changelog
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 545d694..cc0aacd 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -12,6 +12,7 @@
   :class:`~cryptography.hazmat.backends.interfaces.CipherBackend`.
 * Added support for the OpenSSL backend under Windows.
 * Improved thread-safety for the OpenSSL backend.
+* Added PBKDF2HMAC support to OpenSSL backend.
 
 0.1 - 2014-01-08
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