diff --git a/api/DedicatedWorkerGlobalScope.json b/api/DedicatedWorkerGlobalScope.json
index 734f02563714c..ab1fb00b798d5 100644
--- a/api/DedicatedWorkerGlobalScope.json
+++ b/api/DedicatedWorkerGlobalScope.json
@@ -369,6 +369,40 @@
             "deprecated": false
           }
         }
+      },
+      "rtctransform_event": {
+        "__compat": {
+          "description": "<code>rtctransform</code> event",
+          "spec_url": "https://w3c.github.io/webrtc-encoded-transform/#dom-dedicatedworkerglobalscope-onrtctransform",
+          "support": {
+            "chrome": {
+              "version_added": false
+            },
+            "chrome_android": "mirror",
+            "edge": "mirror",
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": "mirror",
+            "ie": {
+              "version_added": false
+            },
+            "oculus": "mirror",
+            "opera": "mirror",
+            "opera_android": "mirror",
+            "safari": {
+              "version_added": "15.4"
+            },
+            "safari_ios": "mirror",
+            "samsunginternet_android": "mirror",
+            "webview_android": "mirror"
+          },
+          "status": {
+            "experimental": true,
+            "standard_track": true,
+            "deprecated": false
+          }
+        }
       }
     }
   }