diff --git a/lib/util/cmcd_manager.js b/lib/util/cmcd_manager.js
index c13a9bb292..6ea7287b96 100644
--- a/lib/util/cmcd_manager.js
+++ b/lib/util/cmcd_manager.js
@@ -31,7 +31,7 @@ shaka.util.CmcdManager = class {
      *
      * @private {string}
      */
-    this.sid_ = config.sessionId || window.crypto.randomUUID();
+    this.sid_ = '';
 
     /**
      * Streaming format
@@ -147,6 +147,10 @@ shaka.util.CmcdManager = class {
    */
   applyTextData(request) {
     try {
+      if (!this.config_.enabled) {
+        return;
+      }
+
       this.apply_(request, {
         ot: shaka.util.CmcdManager.ObjectType.CAPTION,
         su: true,
@@ -217,6 +221,9 @@ shaka.util.CmcdManager = class {
    * @private
    */
   createData_() {
+    if (!this.sid_) {
+      this.sid_ = this.config_.sessionId || window.crypto.randomUUID();
+    }
     return {
       v: shaka.util.CmcdManager.Version,
       sf: this.sf_,