diff --git a/ssh/channel.go b/ssh/channel.go
index 6d82bd4..40f0aa0 100644
--- a/ssh/channel.go
+++ b/ssh/channel.go
@@ -61,7 +61,7 @@ func (c ChannelRequest) Error() string {
 
 // RejectionReason is an enumeration used when rejecting channel creation
 // requests. See RFC 4254, section 5.1.
-type RejectionReason int
+type RejectionReason uint32
 
 const (
 	Prohibited RejectionReason = iota + 1
diff --git a/ssh/messages_test.go b/ssh/messages_test.go
index 24a8bd9..fb94404 100644
--- a/ssh/messages_test.go
+++ b/ssh/messages_test.go
@@ -40,6 +40,7 @@ var messageTypes = []interface{}{
 	&userAuthRequestMsg{},
 	&channelOpenMsg{},
 	&channelOpenConfirmMsg{},
+	&channelOpenFailureMsg{},
 	&channelRequestMsg{},
 	&channelRequestSuccessMsg{},
 }
@@ -124,6 +125,13 @@ func (*kexDHInitMsg) Generate(rand *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(dhi)
 }
 
+// TODO(dfc) maybe this can be removed in the future if testing/quick can handle
+// derived basic types.
+func (RejectionReason) Generate(rand *rand.Rand, size int) reflect.Value {
+	m := RejectionReason(Prohibited)
+	return reflect.ValueOf(m)
+}
+
 var (
 	_kexInitMsg   = new(kexInitMsg).Generate(rand.New(rand.NewSource(0)), 10).Elem().Interface()
 	_kexDHInitMsg = new(kexDHInitMsg).Generate(rand.New(rand.NewSource(0)), 10).Elem().Interface()