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 91aae71a1b4098f171232eceb032a421f30369d7..8b2da7dcf643ddfa56debe9187ef36acfcb53965 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
@@ -31,15 +31,15 @@ class oauthToken
 {
 public:
     oauthToken(QString token, int expiresIn, QString scope, QString tokenType) : m_token(token), m_scope(scope), m_type(tokenType){
-        m_validUntil = time(0) + expiresIn;
+        m_validUntil = time(nullptr) + expiresIn;
     }
     oauthToken(){
-        m_validUntil = time(0) - 1;
+        m_validUntil = time(nullptr) - 1;
     }
     QString getToken(){return m_token;};
     QString getScope(){return m_scope;};
     QString getType(){return m_type;};
-    bool isValid(){return time(0) < m_validUntil;};
+    bool isValid(){return time(nullptr) < m_validUntil;};
 
 private:
     QString m_token;
diff --git a/samples/client/petstore/cpp-qt/client/PFXOauth.h b/samples/client/petstore/cpp-qt/client/PFXOauth.h
index df282d47cee9346b75dc4195f5a89ecf9711fd25..3c3ad8c1c3d54fbe339efe9f2e27e010ab25af54 100644
--- a/samples/client/petstore/cpp-qt/client/PFXOauth.h
+++ b/samples/client/petstore/cpp-qt/client/PFXOauth.h
@@ -39,15 +39,15 @@ class oauthToken
 {
 public:
     oauthToken(QString token, int expiresIn, QString scope, QString tokenType) : m_token(token), m_scope(scope), m_type(tokenType){
-        m_validUntil = time(0) + expiresIn;
+        m_validUntil = time(nullptr) + expiresIn;
     }
     oauthToken(){
-        m_validUntil = time(0) - 1;
+        m_validUntil = time(nullptr) - 1;
     }
     QString getToken(){return m_token;};
     QString getScope(){return m_scope;};
     QString getType(){return m_type;};
-    bool isValid(){return time(0) < m_validUntil;};
+    bool isValid(){return time(nullptr) < m_validUntil;};
 
 private:
     QString m_token;