diff --git a/src/ray/observability/open_telemetry_metric_recorder.h b/src/ray/observability/open_telemetry_metric_recorder.h
index f21181f1739a..c1ada823586d 100644
--- a/src/ray/observability/open_telemetry_metric_recorder.h
+++ b/src/ray/observability/open_telemetry_metric_recorder.h
@@ -14,6 +14,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <opentelemetry/metrics/meter.h>
 #include <opentelemetry/metrics/observer_result.h>
 #include <opentelemetry/metrics/sync_instruments.h>