diff --git a/gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java b/gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
index 5fd8da2..d462b43 100644
--- a/gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
+++ b/gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
@@ -129,7 +129,7 @@
     }
   }
 
-  private static AtomicInteger CHANGE_ID_COUNTER = new AtomicInteger();
+  private static final AtomicInteger CHANGE_ID_COUNTER = new AtomicInteger();
 
   private static String nextChangeId() {
     // Tests use a variety of mechanisms for setting temporary timestamps, so we can't guarantee