diff --git a/src/tracing/agent.h b/src/tracing/agent.h
index 7ee1b417c6ffa0..b542a849fe8da7 100644
--- a/src/tracing/agent.h
+++ b/src/tracing/agent.h
@@ -76,7 +76,7 @@ class AgentWriterHandle {
   inline AgentWriterHandle(Agent* agent, int id) : agent_(agent), id_(id) {}
 
   Agent* agent_ = nullptr;
-  int id_;
+  int id_ = 0;
 
   friend class Agent;
 };