diff --git a/lib/tasks/listen.js b/lib/tasks/listen.js
index 8564bcb1..362664ec 100644
--- a/lib/tasks/listen.js
+++ b/lib/tasks/listen.js
@@ -155,6 +155,13 @@ class TaskListen extends Task {
     const ci = this.nested ? this.parentTask.sd.callInfo : cs.callInfo.toJSON();
     if (this._ignoreCustomerData) {
       delete ci.customerData;
+    } else {
+      for (const key in ci.customerData) {
+        if (ci.customerData.hasOwnProperty(key)) {
+          const value = ci.customerData[key];
+          ci.customerData[key] = typeof value === 'string' ? escapeString(value) : value;
+        }
+      }
     }
     const metadata = Object.assign(
       {sampleRate: this.sampleRate, mixType: this.mixType},