diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookMetrics.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookMetrics.java
index c2046a1..e5dd877 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookMetrics.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookMetrics.java
@@ -47,7 +47,7 @@
             "timeout", new Description("Hook execution timeouts").setRate(), field);
   }
 
-  public Timer1.Context start(String name) {
+  public Timer1.Context<String> start(String name) {
     return latency.start(name);
   }
 
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java
index 4ff5d94..ee59fb4 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java
@@ -85,7 +85,7 @@
   public HookResult runHook() {
     HookResult result = null;
     String name = getName();
-    try (Timer1.Context timer = args.metrics.start(name)) {
+    try (Timer1.Context<String> timer = args.metrics.start(name)) {
       args.metrics.count(name);
       List<String> argv = new ArrayList<>(1 + args.get().size());
       argv.add(hook.toAbsolutePath().toString());