diff --git a/pkg/wsapi/api.go b/pkg/wsapi/api.go
index 9615258..2277257 100644
--- a/pkg/wsapi/api.go
+++ b/pkg/wsapi/api.go
@@ -195,14 +195,16 @@ func (ws *cmdHandler) handleMsg(r io.Reader) error {
 	}
 
 	nd := newData(cmd)
-	err = mapstructure.Decode(&msgMap, &nd)
-	if err != nil {
-		ws.writeError(id, Error{
-			Code:    "invalid_format",
-			Message: err.Error(),
-		})
+	if _, ok := nd.(map[string]interface{}); !ok {
+		err := mapstructure.Decode(&msgMap, &nd)
+		if err != nil {
+			ws.writeError(id, Error{
+				Code:    "invalid_format",
+				Message: err.Error(),
+			})
 
-		return nil
+			return nil
+		}
 	}
 
 	return hand(ws, id, cmd, nd)