diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5AbstractCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5AbstractCodegen.java
index a1d22e00edb8..14398095aa5e 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5AbstractCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5AbstractCodegen.java
@@ -204,7 +204,7 @@ public class CppQt5AbstractCodegen extends AbstractCppCodegen implements Codegen
 
     @Override
     public String toModelFilename(String name) {
-        return modelNamePrefix + sanitizeName(initialCaps(name));
+        return toModelName(name);
     }
     
     /**
diff --git a/modules/openapi-generator/src/main/resources/cpp-qt5-qhttpengine-server/apirouter.h.mustache b/modules/openapi-generator/src/main/resources/cpp-qt5-qhttpengine-server/apirouter.h.mustache
index 47a787fc8fa3..a2789da73316 100644
--- a/modules/openapi-generator/src/main/resources/cpp-qt5-qhttpengine-server/apirouter.h.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-qt5-qhttpengine-server/apirouter.h.mustache
@@ -2,6 +2,7 @@
 #ifndef {{prefix}}_APIROUTER_H
 #define {{prefix}}_APIROUTER_H
 
+#include <functional>
 #include <QObject>
 #include <QStringList>
 #include <QSharedPointer>
diff --git a/samples/server/petstore/cpp-qt5-qhttpengine-server/server/src/handlers/OAIApiRouter.h b/samples/server/petstore/cpp-qt5-qhttpengine-server/server/src/handlers/OAIApiRouter.h
index 573b5052ce68..8aebdece318e 100644
--- a/samples/server/petstore/cpp-qt5-qhttpengine-server/server/src/handlers/OAIApiRouter.h
+++ b/samples/server/petstore/cpp-qt5-qhttpengine-server/server/src/handlers/OAIApiRouter.h
@@ -13,6 +13,7 @@
 #ifndef OAI_APIROUTER_H
 #define OAI_APIROUTER_H
 
+#include <functional>
 #include <QObject>
 #include <QStringList>
 #include <QSharedPointer>