diff --git a/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
index 674bf32..632b168 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
@@ -28,7 +28,7 @@
 @SuppressWarnings("serial")
 @Singleton
 public class GerritPrometheusExporter extends MetricsServlet {
-  CapabilityChecker capabilityChecker;
+  private final CapabilityChecker capabilityChecker;
 
   @Inject
   public GerritPrometheusExporter(MetricRegistry registry, CapabilityChecker capabilityChecker) {
@@ -49,4 +49,6 @@
       httpResponse.sendError(HttpServletResponse.SC_FORBIDDEN, "Forbidden access");
     }
   }
+
+  
 }