diff --git a/biometrics/face/aidl/default/Session.cpp b/biometrics/face/aidl/default/Session.cpp
index 0cb7c95..bf52028 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(