diff --git a/build.gradle b/build.gradle
index a40b1a057..feee3603f 100755
--- a/build.gradle
+++ b/build.gradle
@@ -125,7 +125,7 @@ subprojects {
   }
   
   spotbugs {
-    toolVersion = '4.8.2'
+    toolVersion = '4.8.6'
     excludeFilter = rootProject.file('codequality/findbugs-exclude.xml')
     ignoreFailures = false
     spotbugsMain.enabled = true
diff --git a/spectator-ext-spark/src/main/java/com/netflix/spectator/spark/SparkSink.java b/spectator-ext-spark/src/main/java/com/netflix/spectator/spark/SparkSink.java
index 4df83cbcf..bf966db5e 100644
--- a/spectator-ext-spark/src/main/java/com/netflix/spectator/spark/SparkSink.java
+++ b/spectator-ext-spark/src/main/java/com/netflix/spectator/spark/SparkSink.java
@@ -35,7 +35,7 @@
 /**
  * Sink for exporting spark metrics.
  */
-public class SparkSink implements Sink {
+public final class SparkSink implements Sink {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(SparkSink.class);