diff --git a/message.go b/message.go
index 1dd4bee..ddc5731 100644
--- a/message.go
+++ b/message.go
@@ -34,6 +34,7 @@ const (
 	ReactionDoubleExclamation Reaction = ":bangbang:"
 	ReactionSkull             Reaction = ":skull:"
 	ReactionSpeakingHead      Reaction = ":speaking_head:"
+	ReactionGreenCheck        Reaction = ":white_check_mark:"
 )
 
 // information about attachments to messages