diff --git a/modules/common/src/test/scala/com.snowplowanalytics.snowplow.enrich.common/EtlPipelineSpec.scala b/modules/common/src/test/scala/com.snowplowanalytics.snowplow.enrich.common/EtlPipelineSpec.scala
index 1b052c1e0..7e71e3b46 100644
--- a/modules/common/src/test/scala/com.snowplowanalytics.snowplow.enrich.common/EtlPipelineSpec.scala
+++ b/modules/common/src/test/scala/com.snowplowanalytics.snowplow.enrich.common/EtlPipelineSpec.scala
@@ -103,6 +103,7 @@ class EtlPipelineSpec extends Specification with ValidatedMatchers {
       invalidCollectorPayload
     ) must be like {
       case Validated.Invalid(_: BadRow.CPFormatViolation) :: Nil => ok
+      case other => ko(s"One invalid CPFormatViolation expected, got ${other}")
     }
   }