doctest fix
diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index eda6378..5f4c531 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -406,6 +406,7 @@
     objects stored in this CRL.
 
     .. doctest::
+
             >>> len(crl)
             1
             >>> type(crl[0])