A padding example
diff --git a/docs/primitives/symmetric-encryption.rst b/docs/primitives/symmetric-encryption.rst
index 08724a0..779f087 100644
--- a/docs/primitives/symmetric-encryption.rst
+++ b/docs/primitives/symmetric-encryption.rst
@@ -12,8 +12,8 @@
 
     .. code-block:: pycon
 
-        >>> from cryptography.primitives.block import BlockCipher, cipher, mode
-        >>> cipher = BlockCipher(cipher.AES(key), mode.CBC(iv))
+        >>> from cryptography.primitives.block import BlockCipher, cipher, mode, padding
+        >>> cipher = BlockCipher(cipher.AES(key), mode.CBC(iv, padding.PKCS7()))
         >>> cipher.encrypt("my secret message") + cipher.finalize()
         # The ciphertext
         [...]
@@ -65,3 +65,5 @@
 
 Paddings
 ~~~~~~~~
+
+.. class:: cryptography.primitives.block.padding.PKCS7()