diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticStoredValue.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticStoredValue.java
index a02a715..bd7c1c3 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticStoredValue.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticStoredValue.java
@@ -18,6 +18,7 @@
 
 import com.google.gerrit.index.StoredValue;
 import com.google.gson.JsonElement;
+import com.google.protobuf.MessageLite;
 import java.sql.Timestamp;
 import java.time.Instant;
 import java.time.format.DateTimeFormatter;
@@ -83,4 +84,16 @@
         .map(f -> AbstractElasticIndex.decodeBase64(f.getAsString()))
         .collect(toImmutableList());
   }
+
+  @Override
+  public MessageLite asProto() {
+    // Elasticsearch does not store protos
+    return null;
+  }
+
+  @Override
+  public Iterable<MessageLite> asProtos() {
+    // Elasticsearch does not store protos
+    return null;
+  }
 }