diff --git a/src/frontends/controllers/ControlViewSource.h b/src/frontends/controllers/ControlViewSource.h
index 16a05b7996..9c21fcc4ba 100644
--- a/src/frontends/controllers/ControlViewSource.h
+++ b/src/frontends/controllers/ControlViewSource.h
@@ -35,6 +35,8 @@ public:
 	virtual void dispatchParams() {}
 	///
 	virtual bool isBufferDependent() const { return true; }
+	///
+	bool canApply() const { return true; }
 
 	/// The title displayed by the dialog reflects source type. 
 	docstring const title() const;