diff --git a/src/main/java/com/xeiam/xchart/BitmapEncoder.java b/src/main/java/com/xeiam/xchart/BitmapEncoder.java
index ceabf6dd68a96cb675b09569a4bb9afde7dd5980..463f10d6c20df269fcdeb920066ec0ba5bf55e6a 100644
--- a/src/main/java/com/xeiam/xchart/BitmapEncoder.java
+++ b/src/main/java/com/xeiam/xchart/BitmapEncoder.java
@@ -35,7 +35,7 @@ import javax.imageio.stream.FileImageOutputStream;
  * 
  * @author timmolter
  */
-public class BitmapEncoder {
+public final class BitmapEncoder {
 
   /**
    * Constructor - Private constructor to prevent instantiation
diff --git a/src/main/java/com/xeiam/xchart/ServletEncoder.java b/src/main/java/com/xeiam/xchart/ServletEncoder.java
index ce3120e65e057327abccc0537a863c1263414c00..ca8a699b514b4fbf53c58bd548f5a04b51be06a2 100644
--- a/src/main/java/com/xeiam/xchart/ServletEncoder.java
+++ b/src/main/java/com/xeiam/xchart/ServletEncoder.java
@@ -27,7 +27,7 @@ import javax.servlet.ServletOutputStream;
  * 
  * @author timmolter
  */
-public class ServletEncoder {
+public final class ServletEncoder {
 
   /**
    * Constructor - Private constructor to prevent instantiation