add missing "signing"
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 15a8234..8866cf7 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -514,7 +514,7 @@
 
         .. versionadded:: 0.9
 
-        :param bytes data: PEM formatted certificate request data.
+        :param bytes data: PEM formatted certificate signing request data.
 
         :returns: An instance of
             :class:`~cryptography.x509.CertificateSigningRequest`.