diff --git a/include/xrpl/telemetry/SpanGuard.h b/include/xrpl/telemetry/SpanGuard.h
index bd3e705daa..99caff718f 100644
--- a/include/xrpl/telemetry/SpanGuard.h
+++ b/include/xrpl/telemetry/SpanGuard.h
@@ -126,6 +126,7 @@
 */
 
 #include <array>
+#include <cstddef>
 #include <cstdint>
 #include <exception>
 #include <initializer_list>