diff --git a/src/xrpld/rpc/handlers/ledger/LedgerEntry.cpp b/src/xrpld/rpc/handlers/ledger/LedgerEntry.cpp
index 236712f0c20..2f52668266f 100644
--- a/src/xrpld/rpc/handlers/ledger/LedgerEntry.cpp
+++ b/src/xrpld/rpc/handlers/ledger/LedgerEntry.cpp
@@ -373,9 +373,7 @@ parseDirectoryNode(
         return parseObjectID(params, fieldName);
     }
 
-    if (params.isMember(jss::sub_index) &&
-        (!params[jss::sub_index].isConvertibleTo(json::ValueType::UInt) ||
-         params[jss::sub_index].isBool()))
+    if (params.isMember(jss::sub_index) && ((!params[jss::sub_index].isUInt() && !(params[jss::sub_index].isInt() && params[jss::sub_index].asInt() >= 0)) || params[jss::sub_index].isBool()))
     {
         return LedgerEntryHelpers::invalidFieldError("malformedRequest", jss::sub_index, "number");
     }