diff --git a/lemon/cplex.h b/lemon/cplex.h
--- a/lemon/cplex.h
+++ b/lemon/cplex.h
@@ -93,6 +93,7 @@
 
     virtual int _addCol();
     virtual int _addRow();
+    virtual int _addRow(Value l, ExprIterator b, ExprIterator e, Value u);
 
     virtual void _eraseCol(int i);
     virtual void _eraseRow(int i);