diff --git a/engine/flink/avro-util/src/main/scala/pl/touk/nussknacker/engine/avro/schemaregistry/confluent/formatter/ConfluentAvroMessageFormatter.scala b/engine/flink/avro-util/src/main/scala/pl/touk/nussknacker/engine/avro/schemaregistry/confluent/formatter/ConfluentAvroMessageFormatter.scala
index eb3e3f58759..78290137a83 100644
--- a/engine/flink/avro-util/src/main/scala/pl/touk/nussknacker/engine/avro/schemaregistry/confluent/formatter/ConfluentAvroMessageFormatter.scala
+++ b/engine/flink/avro-util/src/main/scala/pl/touk/nussknacker/engine/avro/schemaregistry/confluent/formatter/ConfluentAvroMessageFormatter.scala
@@ -37,7 +37,7 @@ private[confluent] class ConfluentAvroMessageFormatter(schemaRegistryClient: Sch
       val writer = createDatumWriter(record, schema, useSchemaReflection = false)
       writer.write(record, encoder)
       encoder.flush()
-      val str = bos.toString(StandardCharsets.UTF_8)
+      val str = bos.toString(StandardCharsets.UTF_8.toString)
       // assume the output of encoder is correct or throw Exception trying
       io.circe.parser.parse(str).right.get
     } catch {