diff --git a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToIntDeserializer.java b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToIntDeserializer.java
index e455493..916a0c3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToIntDeserializer.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToIntDeserializer.java
@@ -16,11 +16,12 @@
 
 public class StringToIntDeserializer implements StringDeserializer<Integer> {
 
+  @Override
   public Class<Integer> getTypeClass() {
     return Integer.class;
   }
 
-  @SuppressWarnings("unckecked")
+  @Override
   public Integer fromString(String str) {
     return Integer.parseInt(str);
   }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToLongDeserializer.java b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToLongDeserializer.java
index 0d21a5b..d5d5282 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToLongDeserializer.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToLongDeserializer.java
@@ -16,11 +16,12 @@
 
 public class StringToLongDeserializer implements StringDeserializer<Long> {
 
+  @Override
   public Class<Long> getTypeClass() {
     return Long.class;
   }
 
-  @SuppressWarnings("unckecked")
+  @Override
   public Long fromString(String str) {
     return Long.parseLong(str);
   }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToObjectIdDeserializer.java b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToObjectIdDeserializer.java
index 9a61844..504ae81 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToObjectIdDeserializer.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/validation/dfsrefdb/zookeeper/StringToObjectIdDeserializer.java
@@ -18,11 +18,12 @@
 
 public class StringToObjectIdDeserializer implements StringDeserializer<ObjectId> {
 
+  @Override
   public Class<ObjectId> getTypeClass() {
     return ObjectId.class;
   }
 
-  @SuppressWarnings("unckecked")
+  @Override
   public ObjectId fromString(String str) {
     return ObjectId.fromString(str);
   }