diff --git a/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditRendererToJson.java b/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditRendererToJson.java
index 59c0763..922a789 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditRendererToJson.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditRendererToJson.java
@@ -21,6 +21,7 @@
 import com.google.gerrit.server.AccessPath;
 import com.google.gerrit.server.AuditEvent;
 import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.PropertyMap;
 import com.google.gson.ExclusionStrategy;
 import com.google.gson.FieldAttributes;
 import com.google.gson.Gson;
@@ -47,7 +48,7 @@
                     Integer.class,
                     Integer.TYPE,
                     AccessPath.class,
-                    CurrentUser.PropertyKey.class,
+                    PropertyMap.Key.class,
                     Account.Id.class,
                     AuditRecord.class));
         private final HashSet<String> FORBIDDEN_FIELDS =
diff --git a/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditUser.java b/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditUser.java
index 0bb3280..b68670f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditUser.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/auditsl4j/AuditUser.java
@@ -34,4 +34,9 @@
   public void setUserName(String username) {
     this.username = username;
   }
+
+  @Override
+  public Object getCacheKey() {
+    return getAccountId();
+  }
 }