diff --git a/src/widget.js b/src/widget.js
index c709573b..63bf967f 100644
--- a/src/widget.js
+++ b/src/widget.js
@@ -278,7 +278,8 @@ class ClapperWidget extends Gtk.Grid
 
             if(currStream && type !== 'subtitle') {
                 const caps = currStream.get_caps();
-                debug(`${type} caps: ${caps.to_string()}`);
+                if (caps)
+                    debug(`${type} caps: ${caps.to_string()}`);
             }
             if(type === 'video') {
                 const isShowVis = (