diff --git a/docs/x509.rst b/docs/x509.rst
index e16e79e..262ba30 100644
--- a/docs/x509.rst
+++ b/docs/x509.rst
@@ -188,7 +188,11 @@
 
         Returns the
         :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm` used in
-        the signature.
+        the certificate's signature.
+
+        .. note::
+            Items signed by the parsed certificate do not have to use the same
+            hash algorithm.
 
         .. doctest::