diff --git a/broadcastradio/1.2/ITunerCallback.hal b/broadcastradio/1.2/ITunerCallback.hal
index 223a571..4e3d0a5 100644
--- a/broadcastradio/1.2/ITunerCallback.hal
+++ b/broadcastradio/1.2/ITunerCallback.hal
@@ -19,4 +19,18 @@
 import @1.1::ITunerCallback;
 
 interface ITunerCallback extends @1.1::ITunerCallback {
+    /**
+     * Generic callback for passing updates to vendor-specific parameter values.
+     * The framework does not interpret the parameters, they are passed
+     * in an opaque manner between a vendor application and HAL.
+     *
+     * It's up to the HAL implementation if and how to implement this callback,
+     * as long as it obeys the prefix rule. In particular, only selected keys
+     * may be notified this way. However, setParameters must not trigger
+     * this callback, while an internal event can change parameters
+     * asynchronously.
+     *
+     * @param parameters Vendor-specific key-value pairs.
+     */
+    oneway parametersUpdated(vec<VendorKeyValue> parameters);
 };