diff --git a/cmds/idmap2/idmap2d/Idmap2Service.cpp b/cmds/idmap2/idmap2d/Idmap2Service.cpp
index f84e4b5..8f5e49d 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.cpp
+++ b/cmds/idmap2/idmap2d/Idmap2Service.cpp
@@ -113,7 +113,7 @@
 Status Idmap2Service::createIdmap(const std::string& target_apk_path,
                                   const std::string& overlay_apk_path, int32_t fulfilled_policies,
                                   bool enforce_overlayable, int32_t user_id ATTRIBUTE_UNUSED,
-                                  std::unique_ptr<std::string>* _aidl_return) {
+                                  aidl::nullable<std::string>* _aidl_return) {
   assert(_aidl_return);
   SYSTRACE << "Idmap2Service::createIdmap " << target_apk_path << " " << overlay_apk_path;
   _aidl_return->reset(nullptr);
@@ -155,7 +155,7 @@
     return error("failed to write to idmap path " + idmap_path);
   }
 
-  *_aidl_return = std::make_unique<std::string>(idmap_path);
+  *_aidl_return = aidl::make_nullable<std::string>(idmap_path);
   return ok();
 }
 
diff --git a/cmds/idmap2/idmap2d/Idmap2Service.h b/cmds/idmap2/idmap2d/Idmap2Service.h
index 94d2af4..b6f5136 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.h
+++ b/cmds/idmap2/idmap2d/Idmap2Service.h
@@ -19,9 +19,7 @@
 
 #include <android-base/unique_fd.h>
 #include <binder/BinderService.h>
-
-#include <memory>
-#include <string>
+#include <binder/Nullable.h>
 
 #include "android/os/BnIdmap2.h"
 
@@ -46,7 +44,7 @@
   binder::Status createIdmap(const std::string& target_apk_path,
                              const std::string& overlay_apk_path, int32_t fulfilled_policies,
                              bool enforce_overlayable, int32_t user_id,
-                             std::unique_ptr<std::string>* _aidl_return) override;
+                             aidl::nullable<std::string>* _aidl_return) override;
 };
 
 }  // namespace android::os
diff --git a/services/incremental/IncrementalService.cpp b/services/incremental/IncrementalService.cpp
index 9c9fe8c..cccd0133 100644
--- a/services/incremental/IncrementalService.cpp
+++ b/services/incremental/IncrementalService.cpp
@@ -28,6 +28,7 @@
 #include <androidfw/ZipFileRO.h>
 #include <androidfw/ZipUtils.h>
 #include <binder/BinderService.h>
+#include <binder/Nullable.h>
 #include <binder/ParcelFileDescriptor.h>
 #include <binder/Status.h>
 #include <sys/stat.h>
@@ -1083,7 +1084,7 @@
         return false;
     }
     FileSystemControlParcel fsControlParcel;
-    fsControlParcel.incremental = std::make_unique<IncrementalFileSystemControlParcel>();
+    fsControlParcel.incremental = aidl::make_nullable<IncrementalFileSystemControlParcel>();
     fsControlParcel.incremental->cmd.reset(base::unique_fd(::dup(ifs.control.cmd)));
     fsControlParcel.incremental->pendingReads.reset(
             base::unique_fd(::dup(ifs.control.pendingReads)));