diff --git a/modules/imaging/src/main/scala/instances/ImagingChannelInstances.scala b/modules/imaging/src/main/scala/instances/ImagingChannelInstances.scala
index 3c53b50..d6994e8 100644
--- a/modules/imaging/src/main/scala/instances/ImagingChannelInstances.scala
+++ b/modules/imaging/src/main/scala/instances/ImagingChannelInstances.scala
@@ -8,7 +8,5 @@ import at.ac.oeaw.imba.gerlich.gerlib.numeric.NonnegativeInt
 
 trait ImagingChannelInstances:
   import at.ac.oeaw.imba.gerlich.gerlib.numeric.instances.nonnegativeInt.given
-  given simpleShowForChannel(using
-      ev: SimpleShow[NonnegativeInt]
-  ): SimpleShow[ImagingChannel] =
-    ev.contramap(_.get)
+  given SimpleShow[ImagingChannel] =
+    summon[SimpleShow[NonnegativeInt]].contramap(_.get)