diff --git a/src/vesselbase/ActionWithVessel.h b/src/vesselbase/ActionWithVessel.h
index 81d8af25277a2a7560953e62eae5484a43ccec4e..6d312629944c253ffadd4a7e5965ce24491a7eba 100644
--- a/src/vesselbase/ActionWithVessel.h
+++ b/src/vesselbase/ActionWithVessel.h
@@ -144,7 +144,7 @@ protected:
   unsigned getCurrentTask() const ;
 /// Deactivate all the tasks in the task list
   void deactivateAllTasks();
-/// Deactivate all tasks with i in lower \le  i < upper
+/// Deactivate all tasks with i in lower \f$\le\f$  i < upper
   void deactivateTasksInRange( const unsigned& lower, const unsigned& upper );
 /// Add a task to the full list
   void addTaskToList( const unsigned& taskCode );