diff --git a/modules/openapi-generator/src/main/resources/cpp-qt-client/CMakeLists.txt.mustache b/modules/openapi-generator/src/main/resources/cpp-qt-client/CMakeLists.txt.mustache
index b78e15fb97f..86b1d5affeb 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt-client/CMakeLists.txt.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt-client/CMakeLists.txt.mustache
@@ -12,7 +12,8 @@ else ()
 endif ()
 
 find_package(Qt5Core REQUIRED)
-find_package(Qt5Network REQUIRED){{#contentCompression}}
+find_package(Qt5Network REQUIRED){{#authMethods}}{{#isOAuth}}
+find_package(Qt5Gui REQUIRED){{/isOAuth}}{{/authMethods}}{{#contentCompression}}
 find_package(ZLIB REQUIRED){{/contentCompression}}
 
 add_library(${PROJECT_NAME}
@@ -31,9 +32,9 @@ add_library(${PROJECT_NAME}
     {{prefix}}Helpers.cpp
     {{prefix}}HttpRequest.cpp
     {{prefix}}HttpFileElement.cpp
+    {{prefix}}Oauth.cpp
 )
-target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network {{#contentCompression}} ${ZLIB_LIBRARIES}{{/contentCompression}})
-
+target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network{{#authMethods}}{{#isOAuth}} Qt5::Gui{{/isOAuth}}{{/authMethods}}{{#contentCompression}} ${ZLIB_LIBRARIES}{{/contentCompression}})
 if(NOT APPLE)
   target_link_libraries(${PROJECT_NAME} PRIVATE ssl crypto)
 endif()
diff --git a/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.cpp.mustache b/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.cpp.mustache
index ebe53654851..7d4ec2b44f6 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.cpp.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.cpp.mustache
@@ -1,6 +1,8 @@
 #include "{{prefix}}Oauth.h"
 
-namespace OpenAPI {
+{{#cppNamespaceDeclarations}}
+namespace {{this}} {
+{{/cppNamespaceDeclarations}}
 
 /*
  * Base class to perform oauth2 flows
@@ -343,5 +345,6 @@ void ReplyServer::read()
     emit dataReceived(queryParams);
 }
 
-
-}
\ No newline at end of file
+{{#cppNamespaceDeclarations}}
+} // namespace {{this}}
+{{/cppNamespaceDeclarations}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.h.mustache b/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.h.mustache
index 03aa0dde901..91aae71a1b4 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.h.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt-client/oauth.h.mustache
@@ -21,8 +21,7 @@
 #include <QUrl>
 #include <QUrlQuery>
 #include <QDateTime>
-
-
+#include <time.h>
 
 {{#cppNamespaceDeclarations}}
 namespace {{this}} {
@@ -32,19 +31,19 @@ class oauthToken
 {
 public:
     oauthToken(QString token, int expiresIn, QString scope, QString tokenType) : m_token(token), m_scope(scope), m_type(tokenType){
-        m_validUntil = QDateTime::fromSecsSinceEpoch(QDateTime::currentSecsSinceEpoch() + expiresIn);
+        m_validUntil = time(0) + expiresIn;
     }
     oauthToken(){
-        m_validUntil = QDateTime::fromSecsSinceEpoch(QDateTime::currentSecsSinceEpoch() -1);
+        m_validUntil = time(0) - 1;
     }
     QString getToken(){return m_token;};
     QString getScope(){return m_scope;};
     QString getType(){return m_type;};
-    bool isValid(){return QDateTime::currentDateTime() < m_validUntil;};
+    bool isValid(){return time(0) < m_validUntil;};
 
 private:
     QString m_token;
-    QDateTime m_validUntil;
+    time_t m_validUntil;
     QString m_scope;
     QString m_type;
 };
diff --git a/samples/client/petstore/cpp-qt/CMakeLists.txt b/samples/client/petstore/cpp-qt/CMakeLists.txt
index 5d408c92e72..6938aca8993 100644
--- a/samples/client/petstore/cpp-qt/CMakeLists.txt
+++ b/samples/client/petstore/cpp-qt/CMakeLists.txt
@@ -10,6 +10,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC -Wall -Wno-unused-variable")
 find_package(Qt5Core REQUIRED)
 find_package(Qt5Network REQUIRED)
 find_package(Qt5Test REQUIRED)
+find_package(Qt5Gui REQUIRED)
 
 include_directories(
     ${CMAKE_CURRENT_SOURCE_DIR}/client
@@ -23,7 +24,7 @@ add_executable(${PROJECT_NAME}
     PetStore/UserApiTests.cpp
     )
 target_link_libraries(${PROJECT_NAME} PRIVATE client)
-target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network Qt5::Test)
+target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network Qt5::Test Qt5::Gui)
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 14)
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD_REQUIRED ON)
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_EXTENSIONS OFF)
diff --git a/samples/client/petstore/cpp-qt/client/CMakeLists.txt b/samples/client/petstore/cpp-qt/client/CMakeLists.txt
index 414d1c08636..29b96a13aae 100644
--- a/samples/client/petstore/cpp-qt/client/CMakeLists.txt
+++ b/samples/client/petstore/cpp-qt/client/CMakeLists.txt
@@ -13,6 +13,7 @@ endif ()
 
 find_package(Qt5Core REQUIRED)
 find_package(Qt5Network REQUIRED)
+find_package(Qt5Gui REQUIRED)
 
 add_library(${PROJECT_NAME}
     PFXApiResponse.cpp
@@ -27,9 +28,9 @@ add_library(${PROJECT_NAME}
     PFXHelpers.cpp
     PFXHttpRequest.cpp
     PFXHttpFileElement.cpp
+    PFXOauth.cpp
 )
-target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network )
-
+target_link_libraries(${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Network Qt5::Gui)
 if(NOT APPLE)
   target_link_libraries(${PROJECT_NAME} PRIVATE ssl crypto)
 endif()
diff --git a/samples/client/petstore/cpp-qt/client/PFXOauth.cpp b/samples/client/petstore/cpp-qt/client/PFXOauth.cpp
index a5cc0da2606..f5617124bb5 100644
--- a/samples/client/petstore/cpp-qt/client/PFXOauth.cpp
+++ b/samples/client/petstore/cpp-qt/client/PFXOauth.cpp
@@ -1,6 +1,6 @@
 #include "PFXOauth.h"
 
-namespace OpenAPI {
+namespace test_namespace {
 
 /*
  * Base class to perform oauth2 flows
@@ -343,5 +343,4 @@ void ReplyServer::read()
     emit dataReceived(queryParams);
 }
 
-
-}
\ No newline at end of file
+} // namespace test_namespace
diff --git a/samples/client/petstore/cpp-qt/client/PFXOauth.h b/samples/client/petstore/cpp-qt/client/PFXOauth.h
index f86a29e944f..df282d47cee 100644
--- a/samples/client/petstore/cpp-qt/client/PFXOauth.h
+++ b/samples/client/petstore/cpp-qt/client/PFXOauth.h
@@ -31,8 +31,7 @@
 #include <QUrl>
 #include <QUrlQuery>
 #include <QDateTime>
-
-
+#include <time.h>
 
 namespace test_namespace {
 
@@ -40,19 +39,19 @@ class oauthToken
 {
 public:
     oauthToken(QString token, int expiresIn, QString scope, QString tokenType) : m_token(token), m_scope(scope), m_type(tokenType){
-        m_validUntil = QDateTime::fromSecsSinceEpoch(QDateTime::currentSecsSinceEpoch() + expiresIn);
+        m_validUntil = time(0) + expiresIn;
     }
     oauthToken(){
-        m_validUntil = QDateTime::fromSecsSinceEpoch(QDateTime::currentSecsSinceEpoch() -1);
+        m_validUntil = time(0) - 1;
     }
     QString getToken(){return m_token;};
     QString getScope(){return m_scope;};
     QString getType(){return m_type;};
-    bool isValid(){return QDateTime::currentDateTime() < m_validUntil;};
+    bool isValid(){return time(0) < m_validUntil;};
 
 private:
     QString m_token;
-    QDateTime m_validUntil;
+    time_t m_validUntil;
     QString m_scope;
     QString m_type;
 };