diff --git a/cmds/installd/InstalldNativeService.cpp b/cmds/installd/InstalldNativeService.cpp
index cad7787..71a8740 100644
--- a/cmds/installd/InstalldNativeService.cpp
+++ b/cmds/installd/InstalldNativeService.cpp
@@ -234,12 +234,12 @@
     return ok();
 }
 
-binder::Status checkUidInAppRange(int32_t appUid) {
-    if (FIRST_APPLICATION_UID <= appUid && appUid <= LAST_APPLICATION_UID) {
+binder::Status checkArgumentAppId(int32_t appId) {
+    if (FIRST_APPLICATION_UID <= appId && appId <= LAST_APPLICATION_UID) {
         return ok();
     }
     return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
-                     StringPrintf("UID %d is outside of the range", appUid));
+                     StringPrintf("appId %d is outside of the range", appId));
 }
 
 #define ENFORCE_UID(uid) {                                  \
@@ -302,12 +302,12 @@
         }                                                      \
     }
 
-#define CHECK_ARGUMENT_UID_IN_APP_RANGE(uid)               \
-    {                                                      \
-        binder::Status status = checkUidInAppRange((uid)); \
-        if (!status.isOk()) {                              \
-            return status;                                 \
-        }                                                  \
+#define CHECK_ARGUMENT_APP_ID(appId)                         \
+    {                                                        \
+        binder::Status status = checkArgumentAppId((appId)); \
+        if (!status.isOk()) {                                \
+            return status;                                   \
+        }                                                    \
     }
 
 #ifdef GRANULAR_LOCKS
@@ -411,7 +411,7 @@
 }  // namespace
 
 binder::Status InstalldNativeService::FsveritySetupAuthToken::authenticate(
-        const ParcelFileDescriptor& authFd, int32_t appUid, int32_t userId) {
+        const ParcelFileDescriptor& authFd, int32_t uid) {
     int open_flags = fcntl(authFd.get(), F_GETFL);
     if (open_flags < 0) {
         return exception(binder::Status::EX_SERVICE_SPECIFIC, "fcntl failed");
@@ -426,9 +426,8 @@
         return exception(binder::Status::EX_SECURITY, "Not a regular file");
     }
     // Don't accept a file owned by a different app.
-    uid_t uid = multiuser_get_uid(userId, appUid);
-    if (this->mStatFromAuthFd.st_uid != uid) {
-        return exception(binder::Status::EX_SERVICE_SPECIFIC, "File not owned by appUid");
+    if (this->mStatFromAuthFd.st_uid != (uid_t)uid) {
+        return exception(binder::Status::EX_SERVICE_SPECIFIC, "File not owned by uid");
     }
     return ok();
 }
@@ -3986,7 +3985,7 @@
 // attacker-in-the-middle cannot enable fs-verity on arbitrary app files. If the FD is not writable,
 // return null.
 //
-// appUid and userId are passed for additional ownership check, such that one app can not be
+// app process uid is passed for additional ownership check, such that one app can not be
 // authenticated for another app's file. These parameters are assumed trusted for this purpose of
 // consistency check.
 //
@@ -3994,13 +3993,13 @@
 // Since enabling fs-verity to a file requires no outstanding writable FD, passing the authFd to the
 // server allows the server to hold the only reference (as long as the client app doesn't).
 binder::Status InstalldNativeService::createFsveritySetupAuthToken(
-        const ParcelFileDescriptor& authFd, int32_t appUid, int32_t userId,
+        const ParcelFileDescriptor& authFd, int32_t uid,
         sp<IFsveritySetupAuthToken>* _aidl_return) {
-    CHECK_ARGUMENT_UID_IN_APP_RANGE(appUid);
-    ENFORCE_VALID_USER(userId);
+    CHECK_ARGUMENT_APP_ID(multiuser_get_app_id(uid));
+    ENFORCE_VALID_USER(multiuser_get_user_id(uid));
 
     auto token = sp<FsveritySetupAuthToken>::make();
-    binder::Status status = token->authenticate(authFd, appUid, userId);
+    binder::Status status = token->authenticate(authFd, uid);
     if (!status.isOk()) {
         return status;
     }
diff --git a/cmds/installd/InstalldNativeService.h b/cmds/installd/InstalldNativeService.h
index 1ec092d..88caba7 100644
--- a/cmds/installd/InstalldNativeService.h
+++ b/cmds/installd/InstalldNativeService.h
@@ -44,8 +44,7 @@
     public:
         FsveritySetupAuthToken() : mStatFromAuthFd() {}
 
-        binder::Status authenticate(const android::os::ParcelFileDescriptor& authFd, int32_t appUid,
-                                    int32_t userId);
+        binder::Status authenticate(const android::os::ParcelFileDescriptor& authFd, int32_t uid);
         bool isSameStat(const struct stat& st) const;
 
     private:
@@ -213,7 +212,7 @@
                                      int32_t* _aidl_return);
 
     binder::Status createFsveritySetupAuthToken(const android::os::ParcelFileDescriptor& authFd,
-                                                int32_t appUid, int32_t userId,
+                                                int32_t uid,
                                                 android::sp<IFsveritySetupAuthToken>* _aidl_return);
     binder::Status enableFsverity(const android::sp<IFsveritySetupAuthToken>& authToken,
                                   const std::string& filePath, const std::string& packageName,
diff --git a/cmds/installd/binder/android/os/IInstalld.aidl b/cmds/installd/binder/android/os/IInstalld.aidl
index 8893e38..120d61d 100644
--- a/cmds/installd/binder/android/os/IInstalld.aidl
+++ b/cmds/installd/binder/android/os/IInstalld.aidl
@@ -145,8 +145,7 @@
         //
         // We don't necessarily need a method here, so it's left blank intentionally.
     }
-    IFsveritySetupAuthToken createFsveritySetupAuthToken(in ParcelFileDescriptor authFd, int appUid,
-            int userId);
+    IFsveritySetupAuthToken createFsveritySetupAuthToken(in ParcelFileDescriptor authFd, int uid);
     int enableFsverity(in IFsveritySetupAuthToken authToken, @utf8InCpp String filePath,
             @utf8InCpp String packageName);
 
diff --git a/cmds/installd/tests/installd_service_test.cpp b/cmds/installd/tests/installd_service_test.cpp
index 4bc92af..f2b578a 100644
--- a/cmds/installd/tests/installd_service_test.cpp
+++ b/cmds/installd/tests/installd_service_test.cpp
@@ -548,8 +548,7 @@
         unique_fd ufd(open(path.c_str(), open_mode));
         EXPECT_GE(ufd.get(), 0) << "open failed: " << strerror(errno);
         ParcelFileDescriptor rfd(std::move(ufd));
-        return service->createFsveritySetupAuthToken(std::move(rfd), kTestAppId, kTestUserId,
-                                                     _aidl_return);
+        return service->createFsveritySetupAuthToken(std::move(rfd), kTestAppId, _aidl_return);
     }
 };