diff --git a/java/com/google/gerrit/server/IdentifiedUser.java b/java/com/google/gerrit/server/IdentifiedUser.java
index 65a81f7..eda6e09 100644
--- a/java/com/google/gerrit/server/IdentifiedUser.java
+++ b/java/com/google/gerrit/server/IdentifiedUser.java
@@ -100,30 +100,30 @@
           enablePeerIPInReflogRecord,
           Providers.of(null),
           state,
-          null);
+          /* realUser= */ null);
     }
 
     public IdentifiedUser create(Account.Id id) {
-      return create(null, id);
+      return create(/* remotePeer= */ null, id);
     }
 
     @VisibleForTesting
     @UsedAt(UsedAt.Project.GOOGLE)
     public IdentifiedUser forTest(Account.Id id, PropertyMap properties) {
-      return runAs(null, id, null, properties);
+      return runAs(/* remotePeer= */ null, id, /* caller= */ null, properties);
     }
 
-    public IdentifiedUser create(SocketAddress remotePeer, Account.Id id) {
-      return runAs(remotePeer, id, null);
+    public IdentifiedUser create(@Nullable SocketAddress remotePeer, Account.Id id) {
+      return runAs(remotePeer, id, /* caller= */ null);
     }
 
     public IdentifiedUser runAs(
-        SocketAddress remotePeer, Account.Id id, @Nullable CurrentUser caller) {
+        @Nullable SocketAddress remotePeer, Account.Id id, @Nullable CurrentUser caller) {
       return runAs(remotePeer, id, caller, PropertyMap.EMPTY);
     }
 
     private IdentifiedUser runAs(
-        SocketAddress remotePeer,
+        @Nullable SocketAddress remotePeer,
         Account.Id id,
         @Nullable CurrentUser caller,
         PropertyMap properties) {
@@ -244,7 +244,7 @@
       AccountCache accountCache,
       GroupBackend groupBackend,
       Boolean enablePeerIPInReflogRecord,
-      @Nullable Provider<SocketAddress> remotePeerProvider,
+      Provider<SocketAddress> remotePeerProvider,
       AccountState state,
       @Nullable CurrentUser realUser) {
     this(
@@ -270,7 +270,7 @@
       AccountCache accountCache,
       GroupBackend groupBackend,
       Boolean enablePeerIPInReflogRecord,
-      @Nullable Provider<SocketAddress> remotePeerProvider,
+      Provider<SocketAddress> remotePeerProvider,
       Account.Id id,
       @Nullable CurrentUser realUser,
       PropertyMap properties) {
diff --git a/java/com/google/gerrit/server/account/AccountResolver.java b/java/com/google/gerrit/server/account/AccountResolver.java
index 389b292..fcfc805 100644
--- a/java/com/google/gerrit/server/account/AccountResolver.java
+++ b/java/com/google/gerrit/server/account/AccountResolver.java
@@ -211,7 +211,7 @@
         return searchedAsUser.asIdentifiedUser();
       }
       return userFactory.runAs(
-          null, list.get(0).account().id(), requireNonNull(caller).getRealUser());
+          /* remotePeer= */ null, list.get(0).account().id(), requireNonNull(caller).getRealUser());
     }
 
     @VisibleForTesting
diff --git a/javatests/com/google/gerrit/server/notedb/ChangeNotesTest.java b/javatests/com/google/gerrit/server/notedb/ChangeNotesTest.java
index 61b5e55..9cd002e 100644
--- a/javatests/com/google/gerrit/server/notedb/ChangeNotesTest.java
+++ b/javatests/com/google/gerrit/server/notedb/ChangeNotesTest.java
@@ -825,7 +825,8 @@
         ImmutableList.of(", ", ":\"", ",", "!@#$%^\0&*):\" \n: \r\"#$@,. :");
     for (String strangeTag : strangeTags) {
       Change c = newChange();
-      CurrentUser otherUserAsOwner = userFactory.runAs(null, changeOwner.getAccountId(), otherUser);
+      CurrentUser otherUserAsOwner =
+          userFactory.runAs(/* remotePeer= */ null, changeOwner.getAccountId(), otherUser);
       ChangeUpdate update = newUpdate(c, otherUserAsOwner);
       update.putApproval(LabelId.CODE_REVIEW, (short) 2);
       update.setTag(strangeTag);
diff --git a/javatests/com/google/gerrit/server/notedb/CommitMessageOutputTest.java b/javatests/com/google/gerrit/server/notedb/CommitMessageOutputTest.java
index b53de89..25f2f98 100644
--- a/javatests/com/google/gerrit/server/notedb/CommitMessageOutputTest.java
+++ b/javatests/com/google/gerrit/server/notedb/CommitMessageOutputTest.java
@@ -354,7 +354,8 @@
   @Test
   public void realUser() throws Exception {
     Change c = newChange();
-    CurrentUser ownerAsOtherUser = userFactory.runAs(null, otherUserId, changeOwner);
+    CurrentUser ownerAsOtherUser =
+        userFactory.runAs(/* remotePeer= */ null, otherUserId, changeOwner);
     ChangeUpdate update = newUpdate(c, ownerAsOtherUser);
     update.setChangeMessage("Message on behalf of other user");
     update.commit();
diff --git a/javatests/com/google/gerrit/server/notedb/CommitRewriterTest.java b/javatests/com/google/gerrit/server/notedb/CommitRewriterTest.java
index 5e6803e..527e78e 100644
--- a/javatests/com/google/gerrit/server/notedb/CommitRewriterTest.java
+++ b/javatests/com/google/gerrit/server/notedb/CommitRewriterTest.java
@@ -399,7 +399,9 @@
 
     IdentifiedUser impersonatedChangeOwner =
         this.userFactory.runAs(
-            null, changeOwner.getAccountId(), requireNonNull(otherUser).getRealUser());
+            /* remotePeer= */ null,
+            changeOwner.getAccountId(),
+            requireNonNull(otherUser).getRealUser());
     ChangeUpdate impersonatedChangeMessageUpdate = newUpdate(c, impersonatedChangeOwner);
     impersonatedChangeMessageUpdate.setChangeMessage("Other comment on behalf of");
     impersonatedChangeMessageUpdate.commit();