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: