diff --git a/indexing-hadoop/src/main/java/io/druid/indexer/Bucket.java b/indexing-hadoop/src/main/java/io/druid/indexer/Bucket.java
index ed164a676a9..ddb3455b8de 100644
--- a/indexing-hadoop/src/main/java/io/druid/indexer/Bucket.java
+++ b/indexing-hadoop/src/main/java/io/druid/indexer/Bucket.java
@@ -26,7 +26,7 @@ import java.nio.ByteBuffer;
 
 public class Bucket
 {
-  public static int PREAMBLE_BYTES = 16;
+  public static final int PREAMBLE_BYTES = 16;
 
   /** ID for this bucket, unique for this indexer run. Used for grouping and partitioning. */
   private final int shardNum;
diff --git a/indexing-service/src/main/java/io/druid/indexing/common/config/TaskConfig.java b/indexing-service/src/main/java/io/druid/indexing/common/config/TaskConfig.java
index 1671fb84bd3..a688d2603f2 100644
--- a/indexing-service/src/main/java/io/druid/indexing/common/config/TaskConfig.java
+++ b/indexing-service/src/main/java/io/druid/indexing/common/config/TaskConfig.java
@@ -28,7 +28,7 @@ import java.util.List;
 
 public class TaskConfig
 {
-  public static List<String> DEFAULT_DEFAULT_HADOOP_COORDINATES = ImmutableList.of(
+  public static final List<String> DEFAULT_DEFAULT_HADOOP_COORDINATES = ImmutableList.of(
       "org.apache.hadoop:hadoop-client:2.3.0"
   );
 
diff --git a/processing/src/main/java/io/druid/query/BaseQuery.java b/processing/src/main/java/io/druid/query/BaseQuery.java
index e2052f3ba64..a648f484c78 100644
--- a/processing/src/main/java/io/druid/query/BaseQuery.java
+++ b/processing/src/main/java/io/druid/query/BaseQuery.java
@@ -36,7 +36,7 @@ import java.util.Map;
  */
 public abstract class BaseQuery<T> implements Query<T>
 {
-  public static String QUERYID = "queryId";
+  public static final String QUERYID = "queryId";
   private final DataSource dataSource;
   private final Map<String, Object> context;
   private final QuerySegmentSpec querySegmentSpec;
diff --git a/server/src/main/java/io/druid/client/cache/CacheConfig.java b/server/src/main/java/io/druid/client/cache/CacheConfig.java
index 26c5f383f2d..25c397b7a83 100644
--- a/server/src/main/java/io/druid/client/cache/CacheConfig.java
+++ b/server/src/main/java/io/druid/client/cache/CacheConfig.java
@@ -27,8 +27,8 @@ import java.util.List;
 
 public class CacheConfig
 {
-  public static String USE_CACHE = "useCache";
-  public static String POPULATE_CACHE = "populateCache";
+  public static final String USE_CACHE = "useCache";
+  public static final String POPULATE_CACHE = "populateCache";
 
   @JsonProperty
   private boolean useCache = true;