diff --git a/syncthingconnector/syncthingconnection_requests.cpp b/syncthingconnector/syncthingconnection_requests.cpp
index 6a068ad..3ee0b59 100644
--- a/syncthingconnector/syncthingconnection_requests.cpp
+++ b/syncthingconnector/syncthingconnection_requests.cpp
@@ -1621,7 +1621,13 @@ static void readSyncthingItems(const QJsonArray &array, std::vector<SyncthingIte
         auto &item = into.emplace_back();
         item.name = jsonItemObj.value(QLatin1String("name")).toString();
         item.modificationTime = CppUtilities::DateTime::fromIsoStringGmt(jsonItemObj.value(QLatin1String("modTime")).toString().toUtf8().data());
-        item.size = static_cast<std::size_t>(jsonItemObj.value(QLatin1String("size")).toInteger());
+        item.size = static_cast<std::size_t>(jsonItemObj.value(QLatin1String("size"))
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+                                             .toInteger()
+#else
+                                             .toDouble()
+#endif
+                                             );
         item.index = index;
         item.level = level;
         if (type == QLatin1String("FILE_INFO_TYPE_FILE")) {