diff --git a/transport/HidlLazyUtils.cpp b/transport/HidlLazyUtils.cpp
index 9223af6..429ab8b 100644
--- a/transport/HidlLazyUtils.cpp
+++ b/transport/HidlLazyUtils.cpp
@@ -70,10 +70,10 @@
 Return<void> ClientCounterCallback::onClients(const sp<::android::hidl::base::V1_0::IBase>& service,
                                               bool clients) {
     if (clients) {
-        LOG(INFO) << "HAL " << service->descriptor << " connected.";
+        LOG(INFO) << "HAL " << getDescriptor(service.get()) << " connected.";
         mNumConnectedServices++;
     } else {
-        LOG(INFO) << "HAL " << service->descriptor << " disconnected.";
+        LOG(INFO) << "HAL " << getDescriptor(service.get()) << " disconnected.";
         mNumConnectedServices--;
     }
     LOG(INFO) << "HAL has " << mNumConnectedServices << " (of " << mNumRegisteredServices
@@ -89,11 +89,12 @@
 status_t LazyServiceRegistrarImpl::registerService(
     const sp<::android::hidl::base::V1_0::IBase>& service, const std::string& name) {
     static auto manager = hardware::defaultServiceManager1_2();
-    LOG(INFO) << "Registering HAL: " << service->descriptor << " with name: " << name;
+    LOG(INFO) << "Registering HAL: " << getDescriptor(service.get()) << " with name: " << name;
     status_t res = android::hardware::details::registerAsServiceInternal(service, name);
     if (res == android::OK) {
         mClientCallback->incServiceCounter();
-        bool ret = manager->registerClientCallback(service, mClientCallback);
+        bool ret = manager->registerClientCallback(getDescriptor(service.get()), name, service,
+                                                   mClientCallback);
         if (!ret) {
             res = android::INVALID_OPERATION;
             LOG(ERROR) << "Failed to add client callback";
diff --git a/transport/HidlTransportUtils.cpp b/transport/HidlTransportUtils.cpp
index 4e952eb..8c61281 100644
--- a/transport/HidlTransportUtils.cpp
+++ b/transport/HidlTransportUtils.cpp
@@ -56,6 +56,10 @@
 }
 
 std::string getDescriptor(IBase* interface) {
+    if (interface == nullptr) {
+        return "";
+    }
+
     std::string myDescriptor{};
     auto ret = interface->interfaceDescriptor([&](const hidl_string &types) {
         myDescriptor = types.c_str();
diff --git a/transport/manager/1.2/IClientCallback.hal b/transport/manager/1.2/IClientCallback.hal
index 1189e44..8ebb044 100644
--- a/transport/manager/1.2/IClientCallback.hal
+++ b/transport/manager/1.2/IClientCallback.hal
@@ -21,6 +21,10 @@
      * This is called when there is a transition between having >= 1 clients and having 0 clients
      * (or vice versa).
      *
+     * Upon receiving hasClients false, if the process decides to exit, it is recommended to try to
+     * unregister using @1.2::IServiceManager's tryUnregister before quiting in case another client
+     * associates.
+     *
      * @param registered binder 'server' registered with IServiceManager's registerClientCallback
      * @param hasClients whether there are currently clients
      *     true - when there are >= 1 clients. This must be called as soon as IServiceManager::get
diff --git a/transport/manager/1.2/IServiceManager.hal b/transport/manager/1.2/IServiceManager.hal
index e1629d6..d79403d 100644
--- a/transport/manager/1.2/IServiceManager.hal
+++ b/transport/manager/1.2/IServiceManager.hal
@@ -27,7 +27,9 @@
      * If the service has clients at the time of registration, the callback is called with
      * hasClients true. After that, it is called based on the changes in clientele.
      *
-     * @param server non-null service waiting to have no clients
+     * @param fqName Fully-qualified interface name (used to register)
+     * @param name Instance name (of the registered service)
+     * @param server non-null service waiting to have no clients (previously registered)
      * @param cb non-null callback to call when there are no clients
      * @return success
      *     true on success
@@ -35,7 +37,11 @@
      *      - the server or cb parameters are null
      *      - this is called by a process other than the server process
      */
-    registerClientCallback(interface server, IClientCallback cb) generates (bool success);
+    registerClientCallback(string fqName,
+                           string name,
+                           interface server,
+                           IClientCallback cb)
+        generates (bool success);
 
     /**
      * Removes a callback previously registered with registerClientCallback.
@@ -68,9 +74,32 @@
      *
      * See also @1.0::IServiceManager's listByInterface function.
      *
-     * @param fqName         Fully-qualified interface name.
+     * @param fqName Fully-qualified interface name.
      *
      * @return instanceNames List of instance names running the particular service.
      */
     listManifestByInterface(string fqName) generates (vec<string> instanceNames);
+
+    /**
+     * Unregisters a service if there are no clients for it. This must only unregister the
+     * service if it is called from the same process that registered the service.
+     *
+     * This unregisters all instances of the service, even if they are under a different instance
+     * name.
+     *
+     * Recommended usage is when creating a lazy process, try unregistering when IClientCallback's
+     * onClients(*, false) is called. If this unregister is successful, then it is safe to exit. If
+     * it is unsuccessful, then you can assume a client re-associated with the server. If a process
+     * has multiple servers, and only some succeed in unregistration, then the unregistered services
+     * can be re-registered.
+     *
+     * See also addWithChain and @1.0::IServiceManager's add.
+     *
+     * @param fqName Fully-qualified interface name.
+     * @param name Instance name.
+     * @param service Handle to registering service.
+     *
+     * @return success Whether the service was successfully unregistered.
+     */
+    tryUnregister(string fqName, string name, interface service) generates (bool success);
 };