diff --git a/modules/openapi-generator/src/main/resources/cpp-qt-client/HttpRequest.h.mustache b/modules/openapi-generator/src/main/resources/cpp-qt-client/HttpRequest.h.mustache
index 1ec374f90f89..4566a9c0b0a3 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt-client/HttpRequest.h.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt-client/HttpRequest.h.mustache
@@ -71,7 +71,7 @@ public:
     int  getHttpResponseCode() const;
 
 Q_SIGNALS:
-    void on_execution_finished({{prefix}}HttpRequestWorker *worker);
+    void on_execution_finished({{#cppNamespaceDeclarations}}{{this}}::{{/cppNamespaceDeclarations}}{{prefix}}HttpRequestWorker *worker);
     void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
 
 private:
diff --git a/samples/client/petstore/cpp-qt-addDownloadProgress/client/PFXHttpRequest.h b/samples/client/petstore/cpp-qt-addDownloadProgress/client/PFXHttpRequest.h
index e44027c91c14..3ebd6e1724a1 100644
--- a/samples/client/petstore/cpp-qt-addDownloadProgress/client/PFXHttpRequest.h
+++ b/samples/client/petstore/cpp-qt-addDownloadProgress/client/PFXHttpRequest.h
@@ -79,7 +79,7 @@ class PFXHttpRequestWorker : public QObject {
     int  getHttpResponseCode() const;
 
 Q_SIGNALS:
-    void on_execution_finished(PFXHttpRequestWorker *worker);
+    void on_execution_finished(test_namespace::PFXHttpRequestWorker *worker);
     void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
 
 private:
diff --git a/samples/client/petstore/cpp-qt/client/PFXHttpRequest.h b/samples/client/petstore/cpp-qt/client/PFXHttpRequest.h
index e44027c91c14..3ebd6e1724a1 100644
--- a/samples/client/petstore/cpp-qt/client/PFXHttpRequest.h
+++ b/samples/client/petstore/cpp-qt/client/PFXHttpRequest.h
@@ -79,7 +79,7 @@ class PFXHttpRequestWorker : public QObject {
     int  getHttpResponseCode() const;
 
 Q_SIGNALS:
-    void on_execution_finished(PFXHttpRequestWorker *worker);
+    void on_execution_finished(test_namespace::PFXHttpRequestWorker *worker);
     void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
 
 private: