diff --git a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/.hash b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/.hash
index b8d5097..f5ad87f 100644
--- a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/.hash
+++ b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/.hash
@@ -1 +1 @@
-945de3635b7f5a09244820eef56035c92fdbd324
+3b10f5094c5af9fe551093597fab007d1e148256
diff --git a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/android/hardware/biometrics/face/ISession.aidl b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/android/hardware/biometrics/face/ISession.aidl
index d1c2c1d..7817864 100644
--- a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/android/hardware/biometrics/face/ISession.aidl
+++ b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/1/android/hardware/biometrics/face/ISession.aidl
@@ -37,7 +37,7 @@
   void generateChallenge();
   void revokeChallenge(in long challenge);
   android.hardware.biometrics.face.EnrollmentStageConfig[] getEnrollmentConfig(in android.hardware.biometrics.face.EnrollmentType enrollmentType);
-  android.hardware.biometrics.common.ICancellationSignal enroll(in android.hardware.keymaster.HardwareAuthToken hat, in android.hardware.biometrics.face.EnrollmentType type, in android.hardware.biometrics.face.Feature[] features, in android.hardware.common.NativeHandle previewSurface);
+  android.hardware.biometrics.common.ICancellationSignal enroll(in android.hardware.keymaster.HardwareAuthToken hat, in android.hardware.biometrics.face.EnrollmentType type, in android.hardware.biometrics.face.Feature[] features, in @nullable android.hardware.common.NativeHandle previewSurface);
   android.hardware.biometrics.common.ICancellationSignal authenticate(in long operationId);
   android.hardware.biometrics.common.ICancellationSignal detectInteraction();
   void enumerateEnrollments();
diff --git a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/current/android/hardware/biometrics/face/ISession.aidl b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/current/android/hardware/biometrics/face/ISession.aidl
index d1c2c1d..7817864 100644
--- a/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/current/android/hardware/biometrics/face/ISession.aidl
+++ b/biometrics/face/aidl/aidl_api/android.hardware.biometrics.face/current/android/hardware/biometrics/face/ISession.aidl
@@ -37,7 +37,7 @@
   void generateChallenge();
   void revokeChallenge(in long challenge);
   android.hardware.biometrics.face.EnrollmentStageConfig[] getEnrollmentConfig(in android.hardware.biometrics.face.EnrollmentType enrollmentType);
-  android.hardware.biometrics.common.ICancellationSignal enroll(in android.hardware.keymaster.HardwareAuthToken hat, in android.hardware.biometrics.face.EnrollmentType type, in android.hardware.biometrics.face.Feature[] features, in android.hardware.common.NativeHandle previewSurface);
+  android.hardware.biometrics.common.ICancellationSignal enroll(in android.hardware.keymaster.HardwareAuthToken hat, in android.hardware.biometrics.face.EnrollmentType type, in android.hardware.biometrics.face.Feature[] features, in @nullable android.hardware.common.NativeHandle previewSurface);
   android.hardware.biometrics.common.ICancellationSignal authenticate(in long operationId);
   android.hardware.biometrics.common.ICancellationSignal detectInteraction();
   void enumerateEnrollments();
diff --git a/biometrics/face/aidl/android/hardware/biometrics/face/ISession.aidl b/biometrics/face/aidl/android/hardware/biometrics/face/ISession.aidl
index 2a57e3a..5f06b40 100644
--- a/biometrics/face/aidl/android/hardware/biometrics/face/ISession.aidl
+++ b/biometrics/face/aidl/android/hardware/biometrics/face/ISession.aidl
@@ -154,7 +154,7 @@
      * operation.
      */
     ICancellationSignal enroll(in HardwareAuthToken hat, in EnrollmentType type,
-            in Feature[] features, in NativeHandle previewSurface);
+            in Feature[] features, in @nullable NativeHandle previewSurface);
 
     /**
      * authenticate:
diff --git a/biometrics/face/aidl/default/Session.cpp b/biometrics/face/aidl/default/Session.cpp
index 39f3753..01cb620 100644
--- a/biometrics/face/aidl/default/Session.cpp
+++ b/biometrics/face/aidl/default/Session.cpp
@@ -63,7 +63,8 @@
 
 ndk::ScopedAStatus Session::enroll(
         const keymaster::HardwareAuthToken& /*hat*/, EnrollmentType /*enrollmentType*/,
-        const std::vector<Feature>& /*features*/, const NativeHandle& /*previewSurface*/,
+        const std::vector<Feature>& /*features*/,
+        const std::optional<NativeHandle>& /*previewSurface*/,
         std::shared_ptr<biometrics::common::ICancellationSignal>* /*return_val*/) {
     LOG(INFO) << "enroll";
     if (cb_) {
diff --git a/biometrics/face/aidl/default/Session.h b/biometrics/face/aidl/default/Session.h
index 4d213e3..4152909 100644
--- a/biometrics/face/aidl/default/Session.h
+++ b/biometrics/face/aidl/default/Session.h
@@ -41,7 +41,7 @@
 
     ndk::ScopedAStatus enroll(const keymaster::HardwareAuthToken& hat,
                               EnrollmentType enrollmentType, const std::vector<Feature>& features,
-                              const NativeHandle& previewSurface,
+                              const std::optional<NativeHandle>& previewSurface,
                               std::shared_ptr<common::ICancellationSignal>* return_val) override;
 
     ndk::ScopedAStatus authenticate(
diff --git a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
index 8906b8d..08ab5d6 100644
--- a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
+++ b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
@@ -214,7 +214,7 @@
     auto hat = keymaster::HardwareAuthToken{};
     std::shared_ptr<common::ICancellationSignal> cancellationSignal;
     ASSERT_TRUE(
-            mSession->enroll(hat, EnrollmentType::DEFAULT, {}, NativeHandle{}, &cancellationSignal)
+            mSession->enroll(hat, EnrollmentType::DEFAULT, {}, std::nullopt, &cancellationSignal)
                     .isOk());
 
     // Make sure an error is returned.