make it more obvious that the GCM bugs are with the C backends
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 5b1b81b..51a4c67 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -21,7 +21,7 @@
   and
   :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublickeyWithNumbers`
   support.
-* Fix three GCM related bugs.
+* Work around three GCM related bugs in CommonCrypto and OpenSSL.
 
   * On the CommonCrypto backend adding AAD but not subsequently calling update
     would return null tag bytes.