diff --git a/pkg/whatsmeow/service/whatsmeow.go b/pkg/whatsmeow/service/whatsmeow.go
index 366f0edb..d016db65 100644
--- a/pkg/whatsmeow/service/whatsmeow.go
+++ b/pkg/whatsmeow/service/whatsmeow.go
@@ -1817,12 +1817,15 @@ func (mycli *MyClient) myEventHandler(rawEvt interface{}) {
 		doWebhook = true
 		postMap["event"] = "Archive"
 
-		dataMap := postMap["data"].(map[string]interface{})
-		dataMap["JID"] = evt.JID
-		dataMap["Timestamp"] = evt.Timestamp
-		dataMap["Action"] = evt.Action
-		dataMap["FromFullSync"] = evt.FromFullSync
-		postMap["data"] = dataMap
+		// postMap has no "data" key at this point, so asserting it as a map
+		// panics the whole process whenever a chat is (un)archived on the phone.
+		// Build the payload map directly instead.
+		postMap["data"] = map[string]interface{}{
+			"JID":          evt.JID,
+			"Timestamp":    evt.Timestamp,
+			"Action":       evt.Action,
+			"FromFullSync": evt.FromFullSync,
+		}
 
 		mycli.loggerWrapper.GetLogger(mycli.userID).LogInfo("[%s] Chat archived", mycli.userID)
 	case *events.HistorySync: