s/bit_length/key_size/ (again)
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 444ecb4..db68a64 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -199,12 +199,12 @@
 
     A backend with methods for using RSA.
 
-    .. method:: generate_rsa_private_key(public_exponent, bit_length)
+    .. method:: generate_rsa_private_key(public_exponent, key_size)
 
         :param int public_exponent: The public exponent of the new key.
             Often one of the small Fermat primes 3, 5, 17, 257 or 65537.
 
-        :param int bit_length: The length in bits of the modulus. Should be
+        :param int key_size: The length in bits of the modulus. Should be
             at least 2048.
 
         :return: A new instance of a