diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
index 88ae311..3c376bd 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
@@ -20,6 +20,7 @@
 import com.google.inject.Inject;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
 
 class HookQueue implements LifecycleListener {
@@ -43,7 +44,8 @@
       logger.atFine().log("Hook file not found: %s", hook.toAbsolutePath());
       return;
     }
-    queue.submit(new HookTask.Async(projectName, hook, args));
+    @SuppressWarnings("unused")
+    Future<?> ignored = queue.submit(new HookTask.Async(projectName, hook, args));
   }
 
   @Override