diff --git a/src/libxrpl/ledger/helpers/AccountRootHelpers.cpp b/src/libxrpl/ledger/helpers/AccountRootHelpers.cpp
index 83481a8d12..4365fc8981 100644
--- a/src/libxrpl/ledger/helpers/AccountRootHelpers.cpp
+++ b/src/libxrpl/ledger/helpers/AccountRootHelpers.cpp
@@ -24,6 +24,7 @@
 #include <cstdint>
 #include <limits>
 #include <memory>
+#include <optional>
 #include <set>
 #include <stdexcept>
 #include <vector>