diff --git a/pkg/pmapi/messages.go b/pkg/pmapi/messages.go
index 723a4ba6..892b55c0 100644
--- a/pkg/pmapi/messages.go
+++ b/pkg/pmapi/messages.go
@@ -144,7 +144,7 @@ const messageIDPageSize = 100
 // ConversationIDDomain is used as a placeholder for conversation reference headers to improve compatibility with various clients.
 const ConversationIDDomain = `protonmail.conversationid`
 
-// InternalIDDomain is used as a placeholder for reference/message ID headers to improve compatibility with various clients
+// InternalIDDomain is used as a placeholder for reference/message ID headers to improve compatibility with various clients.
 const InternalIDDomain = `protonmail.internalid`
 
 // InternalReferenceFormat describes format of the message ID (as regex) used for parsing reference headers