diff --git a/src/main/java/com/datadoghq/trace/impl/DDSpanSerializer.java b/src/main/java/com/datadoghq/trace/impl/DDSpanSerializer.java
index 8d8ab97f68..c37ceb62be 100644
--- a/src/main/java/com/datadoghq/trace/impl/DDSpanSerializer.java
+++ b/src/main/java/com/datadoghq/trace/impl/DDSpanSerializer.java
@@ -9,7 +9,7 @@ import io.opentracing.Span;
  */
 public class DDSpanSerializer {
 
-    protected final ObjectMapper objectMapper = new ObjectMapper();
+    private final ObjectMapper objectMapper = new ObjectMapper();
 
     /* (non-Javadoc)
      * @see com.datadoghq.trace.DDSpanSerializer#serialize(io.opentracing.Span)
diff --git a/src/main/java/com/datadoghq/trace/writer/impl/DDAgentWriter.java b/src/main/java/com/datadoghq/trace/writer/impl/DDAgentWriter.java
index 50cb661010..817dd0b2eb 100644
--- a/src/main/java/com/datadoghq/trace/writer/impl/DDAgentWriter.java
+++ b/src/main/java/com/datadoghq/trace/writer/impl/DDAgentWriter.java
@@ -22,18 +22,18 @@ public class DDAgentWriter implements Writer {
     /**
      * Default location of the DD agent
      */
-    protected static final String DEFAULT_HOSTNAME = "localhost";
-    protected static final int DEFAULT_PORT = 8126;
+    private static final String DEFAULT_HOSTNAME = "localhost";
+    private static final int DEFAULT_PORT = 8126;
 
     /**
      * Maximum number of spans kept in memory
      */
-    protected static final int DEFAULT_MAX_SPANS = 1000;
+    private static final int DEFAULT_MAX_SPANS = 1000;
 
     /**
      * Maximum number of traces sent to the DD agent API at once
      */
-    protected static final int DEFAULT_BATCH_SIZE = 10;
+    private static final int DEFAULT_BATCH_SIZE = 10;
 
     /**
      * Used to ensure that we don't keep too many spans (while the blocking queue collect traces...)
diff --git a/src/main/java/com/datadoghq/trace/writer/impl/DDApi.java b/src/main/java/com/datadoghq/trace/writer/impl/DDApi.java
index a11eb15e21..746449b63f 100644
--- a/src/main/java/com/datadoghq/trace/writer/impl/DDApi.java
+++ b/src/main/java/com/datadoghq/trace/writer/impl/DDApi.java
@@ -15,20 +15,20 @@ import java.util.List;
  */
 public class DDApi {
 
-    protected static final Logger logger = LoggerFactory.getLogger(DDApi.class.getName());
+    private static final Logger logger = LoggerFactory.getLogger(DDApi.class.getName());
 
-    protected static final String TRACES_ENDPOINT = "/v0.3/traces";
-    protected static final String SERVICES_ENDPOINT = "/v0.3/services";
+    private static final String TRACES_ENDPOINT = "/v0.3/traces";
+    private static final String SERVICES_ENDPOINT = "/v0.3/services";
 
-    protected final String host;
-    protected final int port;
-    protected final String tracesEndpoint;
-    protected final String servicesEndpoint;
+    private final String host;
+    private final int port;
+    private final String tracesEndpoint;
+    private final String servicesEndpoint;
 
     /**
      * The spans serializer: can be replaced. By default, it serialize in JSON.
      */
-    protected final DDSpanSerializer spanSerializer;
+    private final DDSpanSerializer spanSerializer;
 
     public DDApi(String host, int port) {
         this(host, port, new DDSpanSerializer());
diff --git a/src/main/java/com/datadoghq/trace/writer/impl/LoggingWritter.java b/src/main/java/com/datadoghq/trace/writer/impl/LoggingWritter.java
index be18100ed6..b2197bbf9f 100644
--- a/src/main/java/com/datadoghq/trace/writer/impl/LoggingWritter.java
+++ b/src/main/java/com/datadoghq/trace/writer/impl/LoggingWritter.java
@@ -11,7 +11,7 @@ import io.opentracing.Span;
 
 public class LoggingWritter implements Writer{
 
-	protected static final Logger logger = LoggerFactory.getLogger(LoggingWritter.class.getName());
+	private static final Logger logger = LoggerFactory.getLogger(LoggingWritter.class.getName());
 	
 	@Override
 	public void write(List<Span> trace) {