diff --git a/modules/openapi-generator/src/main/resources/cpp-qt5-client/helpers-header.mustache b/modules/openapi-generator/src/main/resources/cpp-qt5-client/helpers-header.mustache
index 994ae817630..1a91100adf9 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt5-client/helpers-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt5-client/helpers-header.mustache
@@ -10,6 +10,7 @@
 #include <QJsonValue>
 #include <QList>
 #include <QMap>
+#include <QSet>
 #include <QVariant>
 
 #include "{{prefix}}Enum.h"
diff --git a/samples/client/petstore/cpp-qt5/client/PFXHelpers.h b/samples/client/petstore/cpp-qt5/client/PFXHelpers.h
index a0d2c4d47a4..20b4a6f5e15 100644
--- a/samples/client/petstore/cpp-qt5/client/PFXHelpers.h
+++ b/samples/client/petstore/cpp-qt5/client/PFXHelpers.h
@@ -20,6 +20,7 @@
 #include <QJsonValue>
 #include <QList>
 #include <QMap>
+#include <QSet>
 #include <QVariant>
 
 #include "PFXEnum.h"