diff --git a/src/plugins/qmldesigner/designercore/include/nodeinstanceserverinterface.h b/src/plugins/qmldesigner/designercore/include/nodeinstanceserverinterface.h
index 87ad2f685b0..0337dba8bd3 100644
--- a/src/plugins/qmldesigner/designercore/include/nodeinstanceserverinterface.h
+++ b/src/plugins/qmldesigner/designercore/include/nodeinstanceserverinterface.h
@@ -80,7 +80,7 @@ public:
     virtual void changeState(const ChangeStateCommand &command) = 0;
     virtual void addImport(const AddImportCommand &command) = 0;
     virtual void completeComponent(const CompleteComponentCommand &command) = 0;
-    virtual void changeCustomParserSource(ChangeCustomParserSourceCommand &command) = 0;
+    virtual void changeCustomParserSource(const ChangeCustomParserSourceCommand &command) = 0;
 
     static void registerCommands();
 };
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.cpp b/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.cpp
index 559d77ee7ed..8063426a96e 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.cpp
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.cpp
@@ -264,7 +264,7 @@ void NodeInstanceClientProxy::completeComponent(const CompleteComponentCommand &
     nodeInstanceServer()->completeComponent(command);
 }
 
-void NodeInstanceClientProxy::changeCustomParserSource(ChangeCustomParserSourceCommand &command)
+void NodeInstanceClientProxy::changeCustomParserSource(const ChangeCustomParserSourceCommand &command)
 {
     nodeInstanceServer()->changeCustomParserSource(command);
 }
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.h b/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.h
index c2256dfe016..6664fe855a3 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.h
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceclientproxy.h
@@ -97,7 +97,7 @@ protected:
     void changeState(const ChangeStateCommand &command);
     void addImport(const AddImportCommand &command);
     void completeComponent(const CompleteComponentCommand &command);
-    void changeCustomParserSource(ChangeCustomParserSourceCommand &command);
+    void changeCustomParserSource(const ChangeCustomParserSourceCommand &command);
 
 private slots:
     void readDataStream();
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.cpp b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.cpp
index e1aae61aad4..73bba35529c 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.cpp
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.cpp
@@ -346,7 +346,7 @@ void NodeInstanceServer::completeComponent(const CompleteComponentCommand &comma
     startRenderTimer();
 }
 
-void NodeInstanceServer::changeCustomParserSource(ChangeCustomParserSourceCommand &command)
+void NodeInstanceServer::changeCustomParserSource(const ChangeCustomParserSourceCommand &command)
 {
     if (hasInstanceForId(command.instanceId())) {
         ServerNodeInstance instance = instanceForId(command.instanceId());
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.h b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.h
index 303d7c5558d..4475f1d4f02 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.h
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserver.h
@@ -90,7 +90,7 @@ public:
     void changeState(const ChangeStateCommand &command);
     void addImport(const AddImportCommand &command);
     void completeComponent(const CompleteComponentCommand &command);
-    void changeCustomParserSource(ChangeCustomParserSourceCommand &command);
+    void changeCustomParserSource(const ChangeCustomParserSourceCommand &command);
 
     ServerNodeInstance instanceForId(qint32 id) const;
     bool hasInstanceForId(qint32 id) const;
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.cpp b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.cpp
index 7f85ef2ecf1..62f8fa7ee17 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.cpp
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.cpp
@@ -453,7 +453,7 @@ void NodeInstanceServerProxy::completeComponent(const CompleteComponentCommand &
     writeCommand(QVariant::fromValue(command));
 }
 
-void NodeInstanceServerProxy::changeCustomParserSource(ChangeCustomParserSourceCommand &command)
+void NodeInstanceServerProxy::changeCustomParserSource(const ChangeCustomParserSourceCommand &command)
 {
     writeCommand(QVariant::fromValue(command));
 }
diff --git a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.h b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.h
index 2643a2027b2..97c89333fa7 100644
--- a/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.h
+++ b/src/plugins/qmldesigner/designercore/instances/nodeinstanceserverproxy.h
@@ -70,7 +70,7 @@ public:
     void changeState(const ChangeStateCommand &command);
     void addImport(const AddImportCommand &command);
     void completeComponent(const CompleteComponentCommand &command);
-    void changeCustomParserSource(ChangeCustomParserSourceCommand &command);
+    void changeCustomParserSource(const ChangeCustomParserSourceCommand &command);
 
 protected:
     void writeCommand(const QVariant &command);