diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index f3def84..55b2dcd 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -269,6 +269,7 @@
     .. doctest::
 
         >>> import os
+        >>> from cryptography.hazmat.primitives.ciphers.modes import CBC
         >>> iv = os.urandom(16)
         >>> mode = CBC(iv)
 
@@ -276,6 +277,7 @@
 
     .. doctest::
 
+        >>> from cryptography.hazmat.primitives.ciphers.modes import CBC
         >>> iv = "a" * 16
         >>> mode = CBC(iv)