diff --git a/docs/users_guide/7.4.1-notes.xml b/docs/users_guide/7.4.1-notes.xml
index c8dcc3fbddf88596664c271f03a659ce2f0444e1..be38a210b10e1a9eb644c368b6cee24775ccb993 100644
--- a/docs/users_guide/7.4.1-notes.xml
+++ b/docs/users_guide/7.4.1-notes.xml
@@ -209,6 +209,8 @@ instance Typeable []   where typeOf _ = TypeRep
                 </para>
 
                 <para>
+                    This feature is not yet fully mature, but please
+                    do file bug reports if you run into problems.
                     See
                     <xref linkend="kind-polymorphism" />
                     for more information.