diff --git a/cmd/bucket-notification-datatypes.go b/cmd/bucket-notification-datatypes.go
index 3be763e37..8398da11f 100644
--- a/cmd/bucket-notification-datatypes.go
+++ b/cmd/bucket-notification-datatypes.go
@@ -139,8 +139,8 @@ type objectMeta struct {
 	Key         string            `json:"key"`
 	Size        int64             `json:"size,omitempty"`
 	ETag        string            `json:"eTag,omitempty"`
-	ContentType string            `json:"contentType:omitempty"`
-	UserDefined map[string]string `json:"userDefined:omitempty"`
+	ContentType string            `json:"contentType,omitempty"`
+	UserDefined map[string]string `json:"userDefined,omitempty"`
 	VersionID   string            `json:"versionId,omitempty"`
 	Sequencer   string            `json:"sequencer"`
 }