diff --git a/docs/hazmat/primitives/asymmetric/serialization.rst b/docs/hazmat/primitives/asymmetric/serialization.rst
index 87a4dbf..87f3c0b 100644
--- a/docs/hazmat/primitives/asymmetric/serialization.rst
+++ b/docs/hazmat/primitives/asymmetric/serialization.rst
@@ -75,12 +75,12 @@
     .. doctest::
 
         >>> from cryptography.hazmat.backends import default_backend
-        >>> from cryptography.hazmat.primitives.asymmetric import rsa
+        >>> from cryptography.hazmat.primitives.asymmetric import dsa, rsa
         >>> from cryptography.hazmat.primitives.serialization import load_pem_private_key
         >>> key = load_pem_private_key(pem_data, password=None, backend=default_backend())
         >>> if isinstance(key, rsa.RSAPrivateKey):
         ...     signature = sign_with_rsa_key(key, message)
-        ... elif isinstance(key, interfaces.DSAPrivateKey):
+        ... elif isinstance(key, dsa.DSAPrivateKey):
         ...     signature = sign_with_dsa_key(key, message)
         ... else:
         ...     raise TypeError