diff --git a/docs/tuning.md b/docs/tuning.md
index 843380b9a28829898877dd092018e1b31ddabca5..32c7ab86e9991e11228ecc1f3363654027682f0f 100644
--- a/docs/tuning.md
+++ b/docs/tuning.md
@@ -49,7 +49,7 @@ Finally, to register your classes with Kryo, create a public class that extends
 {% highlight scala %}
 import com.esotericsoftware.kryo.Kryo
 
-class MyRegistrator extends KryoRegistrator {
+class MyRegistrator extends spark.KryoRegistrator {
   override def registerClasses(kryo: Kryo) {
     kryo.register(classOf[MyClass1])
     kryo.register(classOf[MyClass2])