diff --git a/lib/tasks/dial.js b/lib/tasks/dial.js
index 36952b38..a4def295 100644
--- a/lib/tasks/dial.js
+++ b/lib/tasks/dial.js
@@ -406,7 +406,7 @@ class TaskDial extends Task {
       this._killOutdials();
     }, this.timeout * 1000);
 
-    this.span.setAttributes('dial.target', JSON.stringify(this.target));
+    this.span.setAttributes({'dial.target': JSON.stringify(this.target)});
     this.target.forEach(async(t) => {
       try {
         t.url = t.url || this.confirmUrl;