Parameter value is never used

[jsabin]

When using the extension like this:

import ai.x.play.json.Encoders.encoder
import ai.x.play.json.Jsonx
...
implicit lazy val jsonFormat: OFormat[TenantAppFilter] = Jsonx.formatCaseClass[TenantAppFilter]

and using the compiler options

scalacOptions += "-Ywarn-macros:after"

I get the following error where the parameter number is different each time I compile:

[error] TenantAppFilterUI.scala:17:81: parameter value x$6 in value $anonfun is never used
[error]   implicit lazy val jsonFormat: OFormat[TenantAppFilter] = Jsonx.formatCaseClass[TenantAppFilter]

Anyway to resolve this error short of removing the compiler option?