diff --git a/protocol/kafka_confluent/v2/message.go b/protocol/kafka_confluent/v2/message.go
index 164879a11..43df8d4ff 100644
--- a/protocol/kafka_confluent/v2/message.go
+++ b/protocol/kafka_confluent/v2/message.go
@@ -11,14 +11,15 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/confluentinc/confluent-kafka-go/v2/kafka"
+
 	"github.com/cloudevents/sdk-go/v2/binding"
 	"github.com/cloudevents/sdk-go/v2/binding/format"
 	"github.com/cloudevents/sdk-go/v2/binding/spec"
-	"github.com/confluentinc/confluent-kafka-go/v2/kafka"
 )
 
 const (
-	prefix         = "ce-"
+	prefix         = "ce_"
 	contentTypeKey = "content-type"
 )
 
diff --git a/protocol/kafka_confluent/v2/message_test.go b/protocol/kafka_confluent/v2/message_test.go
index e7f599b63..9676fe7ac 100644
--- a/protocol/kafka_confluent/v2/message_test.go
+++ b/protocol/kafka_confluent/v2/message_test.go
@@ -42,14 +42,14 @@ var (
 		TopicPartition: topicPartition,
 		Value:          []byte("hello world!"),
 		Headers: mapToKafkaHeaders(map[string]string{
-			"ce-type":            testEvent.Type(),
-			"ce-source":          testEvent.Source(),
-			"ce-id":              testEvent.ID(),
-			"ce-time":            test.Timestamp.String(),
-			"ce-specversion":     "1.0",
-			"ce-dataschema":      test.Schema.String(),
-			"ce-datacontenttype": "text/json",
-			"ce-subject":         "receiverTopic",
+			"ce_type":            testEvent.Type(),
+			"ce_source":          testEvent.Source(),
+			"ce_id":              testEvent.ID(),
+			"ce_time":            test.Timestamp.String(),
+			"ce_specversion":     "1.0",
+			"ce_dataschema":      test.Schema.String(),
+			"ce_datacontenttype": "text/json",
+			"ce_subject":         "receiverTopic",
 			"exta":               "someext",
 		}),
 	}
@@ -89,14 +89,14 @@ func TestNewMessage(t *testing.T) {
 				TopicPartition: topicPartition,
 				Value:          nil,
 				Headers: mapToKafkaHeaders(map[string]string{
-					"ce-type":            testEvent.Type(),
-					"ce-source":          testEvent.Source(),
-					"ce-id":              testEvent.ID(),
-					"ce-time":            test.Timestamp.String(),
-					"ce-specversion":     "1.0",
-					"ce-dataschema":      test.Schema.String(),
-					"ce-datacontenttype": "text/json",
-					"ce-subject":         "receiverTopic",
+					"ce_type":            testEvent.Type(),
+					"ce_source":          testEvent.Source(),
+					"ce_id":              testEvent.ID(),
+					"ce_time":            test.Timestamp.String(),
+					"ce_specversion":     "1.0",
+					"ce_dataschema":      test.Schema.String(),
+					"ce_datacontenttype": "text/json",
+					"ce_subject":         "receiverTopic",
 				}),
 			},
 			expectedEncoding: binding.EncodingBinary,